SKU: 16759487392

Onguard Mastiff Chain and U-Lock Bike Lock

Sale price$77.39 Regular price$85.99
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Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 24 - Jul 29

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For Your Every Summer RSVP, with Code: SUMMER15

Description

Onguard Mastiff Chain and U-Lock Bike LockDESCRIPTION Secure your bike with confidence using the Onguard Mastiff 10mm Chain and U Lock, a heavy duty anti theft security system designed to protect valuable bikes and e bikes in urban environments. Built with hardened steel links and advanced locking technology, it delivers powerful protection against cutting, sawing and tampering. Engineered for maximum durability and versatility, the hexagonal chain links and reinforced U lock design work

DESCRIPTION

Secure your bike with confidence using the Onguard Mastiff 10mm Chain and U Lock, a heavy-duty anti-theft security system designed to protect valuable bikes and e-bikes in urban environments.

Built with hardened steel links and advanced locking technology, it delivers powerful protection against cutting, sawing and tampering.

Engineered for maximum durability and versatility, the hexagonal chain links and reinforced U lock design work together to eliminate weak points while making attacks extremely difficult.

With a protective nylon cover, this premium security chain helps safeguard your bike while preventing damage to paintwork and finishes.

Whether locking your bike at home, work or in the city, it provides dependable high security protection.

 

KEY FEATURES

  • 10mm Hexagonal Hardened Steel Chain: Provides superior resistance against cutting and sawing for high level anti-theft protection
  • Titanium Surface Hardening Technology: Increases resistance to cutting tools and prolongs the life of the security chain
  • X4P Quattro Bolt Locking Mechanism: Secures the shackle on four sides to eliminate leverage points and improve attack resistance
  • Bump Proof Z Cylinder Lock Core: Protects against picking drilling and forced entry for enhanced security
  • Short Shackle Box U Lock Design: Reduces leverage opportunities and strengthens overall locking protection
  • Cinching Loop Chain System: Allows flexible locking around frames wheels or fixed objects for versatile security options
  • Protective Nylon Chain Cover with Velcro Fastening: Prevents scratches to bike paint while keeping the chain securely covered
  • Co Molded Rubber Coated Shackle Protection: Helps protect your bike frame and components from accidental contact
  • Automatic Keyway Protection Cover: Seals the lock cylinder to protect internal components from dirt moisture and weather
  • Five Laser Cut Security Keys Included: Provides multiple spare keys including one with integrated micro-LED for improved visibility

 

SPECIFICATION
  • Product Name: Onguard Mastiff 10mm Chain and U Lock
  • Product Type: Heavy duty anti-theft security chain and U lock for bikes and e-bikes
  • Chain Link Design: Hexagonal and square hardened steel links for increased cutting resistance
  • Chain Diameter: 10 mm hardened steel
  • Available Chain Lengths: 110 cm, 130 cm, 180 cm
  • Lock Type: Short shackle box style U lock
  • Shackle Diameter: 14 mm hardened steel
  • Locking Mechanism: X4P Quattro Bolt four sided locking system
  • Cylinder Type: Bump proof Z Cylinder
  • Key Type: Laser cut security keys
  • Keys Included: 5 keys including 1 key with integrated micro-LED
  • Chain Cover: Protective embroidered nylon cover with Velcro fastening
  • Weather Protection: Automatic keyway cover protects lock internals from elements

 

DELIVERY

FREE & FAST DELIVERY

Delivery time is between 3-5 working days from the date you placed your order.

Bikes and accessories may be delivered separately.

Once your order has been placed, assuming it is in stock and available for dispatch, we will charge your card and your order will be dispatched within 5 working days. We will send you tracking details by email within 48 hours of your order being dispatched. If you have not received tracking details within 6 working days, please reach out to us via email at [email protected] so that we can help.

Please note that deliveries outside of the UK Mainland may be subject to additional charges.

 

MISSED DELIVERIES

Once your order is ready for dispatch, either we or our designated courier will contact you via email, telephone or SMS with tracking information and where applicable, to arrange a suitable delivery window. Please ensure that someone is present at the specified delivery address to receive and sign for your item. If you need to reschedule your delivery, we kindly ask that you notify us or the courier as soon as possible.

Please be aware that once a delivery slot has been confirmed, we cannot guarantee changes can be accommodated without sufficient notice.

Important: If a delivery attempt fails and a new date or time must be arranged, you may be liable for paying the redelivery cost. 

Please see full details of our Shipping & Delivery Policy here

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 16759487392

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4.3 ★★★★★
Based on 21 reviews
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C
Verified Purchase
Cookie
Battle Creek, US
★★★★★ 5
Socks
Size: Medium, Color: (001) Black / Black / White
Great price, perfect fit.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 23, 2026
G
Verified Purchase
Glass
Draper, US
★★★★★ 5
I stay on your foot they don’t slip in your shoe
Number of Items: 3, Color: White/Neutral (3-pairs), Size: Medium
This is the only socks I wear Under Armour because they stay in place I wear a size 8, but they’re more comfortable with a large instead of a medium, but I wear both because I have them already and you can pull them to stretch them out a little bit
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 12, 2026
L
Verified Purchase
Lauren
Louisville, US
★★★★★ 5
Great fit, truly doesn’t slide off heel
Number of Items: 3, Color: White/Neutral (3-pairs), Size: Medium, Number of Items: 3, Color: White/Neutral (3-pairs), Size: Medium
I’ve scoured all the lands looking for a no-show sock that was 1) thin, 2) quality, soft, breathable material, 3) didn’t dig into my feet/heels, 4) doesn’t shrink, and most importantly 5) stays on the back of my heel without a bulky non-slip rubber piece and these check all the boxes! Perfect for low profile women’s work shoes like Keds, etc. Not low enough for most flats though. I wear a women’s size 9.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 19, 2025
E
Verified Purchase
Elliz
Charlottesville, US
★★★★★ 5
So good - I’m buying MORE.
Number of Items: 3, Color: White (3-pairs), Size: Medium
I’m gonna give you more detail than you need about why I’m buying these socks again. I’ve been the mom of girl athletes. I’ve been a model and a fashion director. I’ve worn every brand of shoe on the planet and never found a shoe that did NOT find a vulnerable spot on my foot to rub raw. Even my beloved white Jack Purcell sneakers. With that said - I don’t like socks. I’ve bought a TON of them in 35+ years.....all major brands. They shift. They lose their shape. They get holes in them and wear out too fast. Not these. I retired this year, and knowing I’d be in sneakers a lot, traveling, sightseeing ...... I bought these 6 months ago and have worn them constantly. I’ve traveled with them. I’ve washed them in hot water and bleach. The socks are like brand new. They are exactly the right cut so as not to be seen in a basic sneaker. The little silicone patch on the heel stays put. Not once have I had to dig down into my shoe and pull the sock back up. The socks have stayed soft and EXACTLY the same as the day they were new. Like I said - I am back to buy them again. Great quality!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 20, 2021
J
Verified Purchase
Judy Fletcher
Boise, US
★★★★★ 5
No slip low socks
Number of Items: 3, Color: Black/White (3-pairs), Size: Medium
Perfect! ❤️ these!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 16, 2026

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