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ONGUARD

OnGuard 8020 Mastiff Integrated Key Chain Lock - 3.57' X 0.39"[110CM X 10MM] Black

  • Based on 503 reviews
Condition: New
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Availability: In Stock.
Fulfilled by Amazon
Arrives Friday, Sep 12
Order within 16 hours and 14 minutes
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Size: 10mm x 3.5 ft


Features

  • Integrated Lock: X2P Dual Lock Down head with double rubber cover.
  • Heavy-Duty Chain: 3.5-foot titanium-reinforced, hardened steel hexagonal link chain.
  • High Security: Ideal for medium to high protection.
  • Enhanced Protection: Z-Cylinder resists picking, pulling, and drilling.
  • Extra Keys: Includes 5 laser-cut keys, 1 with micro-LED.

Description

The OnGuard Mastiff 3.5' Chain with Integrated Key Lock features a 3.5-foot, 10mm titanium reinforced, hardened steel hexagonal link chain with an integrated X2P Dual Lock Down head. The double rubber cover provides better protection against bumps and hits. This chain lock offers superior protection for medium to high crime areas and includes a variety of features to ensure maximum security.

Brand: ONGUARD


Special Feature: Heavy Duty


Lock Type: Key Lock


Item dimensions L x W x H: 11.5 x 8 x 3 inches


Material: Rubber


Brand: ‎ONGUARD


Special Feature: ‎Heavy Duty


Lock Type: ‎Key Lock


Item dimensions L x W x H: ‎11.5 x 8 x 3 inches


Material: ‎Rubber


Recommended Uses For Product: ‎Security, Cycling


Style: ‎Modern


Color: ‎Black


Number of Pieces: ‎1


Finish Type: ‎Painted


Included Components: ‎ONGUARD 8020


Controller Type: ‎Hand Control


Shape: ‎Square


Item Weight: ‎1.9 Pounds


Control Method: ‎App


UPC: ‎768661281328 768661280208


Model Name: ‎45008020


Global Trade Identification Number: ‎08


Manufacturer: ‎ONGUARD


Item Weight: ‎1.91 pounds


Product Dimensions: ‎11.5 x 8 x 3 inches


Item model number: ‎8020


Is Discontinued By Manufacturer: ‎No


Exterior: ‎Painted


Manufacturer Part Number: ‎8020


Special Features: ‎Heavy Duty


Date First Available: November 17, 2011


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Friday, Sep 12

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

  • Klarna Financing
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  • Affirm Financing
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  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Similar Products

Top Amazon Reviews

    • Great lock ,
Size: 6' x 3/8""
Great lock, however way to heavy 10 pounds for the weight of this bike lock.
Reviewed in the United States on June 15, 2025 by Don
    • Heavy duty and just plain heavy! But very secure!
Size: 6' x 3/8""
Like carrying a tow chain. I will only use this when my bike needs to be left outdoors. Not something you’ll carry on a ride. But, it’s what I expected and definitely serves its purpose. Don’t buy it if you are expecting it to be light.
Reviewed in the United States on July 2, 2025 by Mike Tucson
    • Heavy chain, scary padlock!
Size: 6' x 3/8""
The 10mm chain is substantial. The padlock size took me aback when I first unwrapped it. The lock mechanism is smooth and easy to use. I like that the lock has a rubber coating on the U portion. I was somewhat surprised by the amount of plastic sheathing on the lock, but it does appear sturdy. I bought an OKC noose chain to go with (my Scouting unit often goes on group rides to the movies, etc., so this extends the group coverage while we're inside). The OKC links are narrower, but do slide over the lock (displacing some of the rubber coating). The OnGuard chain is robust. I could slide the nice cover enough to check all the link welds which looked good. Hoping to get many an event-free year with this lock and chain. Nothing will deter a determined thief, but this will at least divert attention elsewhere. When we go away, the lock and chains are used to secure our bikes to the floor anchor. ... show more
Reviewed in the United States on July 23, 2023 by KCCjr
    • Solid. Bulky solid. Legit.
Size: 10mm x 3.5 ft
This lock is no joke. The chain is heavy and there is no denying that. The lock is a bit silly in my opinion. The key doesn’t easily slide in and it’s very ambiguous as to whether it’s locked or not (click feel when turning key). The key doesn’t come out when it’s unlocked - which is very clear - but I would rather have a more traditional @click - it’s locked” type of feel. ... show more
Reviewed in the United States on April 14, 2024 by Nathaniel P Molgren
    • Awesome, super heavy duty lock and chain
Size: 6' x 3/8""
I've had this for several years and LOVE it! When I have to leave my bike on my rack in truck I leave this on it and feel 100 secure cause it's a huge beast. It's REALLY heavy and it is awkward but it's worth it to know it's locked up safe. I spent hours reviewing bike locks and chains before buying this and a big time review in NYC couldn't get through it even with battery powered tools. And it's not even expensive considering what it is. ... show more
Reviewed in the United States on November 29, 2018 by Seth
    • This product is Amazing
Size: 10mm x 3.5 ft
very solid chain lock , it passed a bolt cutter test . the bolt cutters were useless , like i said ROCK SOLID PRODUCT , EVEN A GRINDER WOULD TAKE SOME TIME AND DRAW ATTENTION . 5 STARS
Reviewed in the United States on October 25, 2024 by Christopher J. Pane
    • Bent key
Size: 10mm x 3.5 ft
One of the keys arrived bent and is unusable. Luckily each lock comes with 5 keys, so it's not a big deal.
Reviewed in the United States on July 27, 2025 by Catherine Heim
    • Not for your average bike
Size: 6' x 3/8""
Definitely secure but don’t get this if you don’t lift weight bec it’s heavier than an average bike.
Reviewed in the United States on August 14, 2025 by Carol Marinera

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