Review on Heavy Duty Seatylock Mason U Lock - Patented Diamond Secure Anti Theft Bike Lock With Keys - Ultimate Protection For City, Electric, Mountain Bikes, And Scooters by Russell Robertson

For the money, this is reasonable quality. I think the loop length is a bit short, which limits it's use slightly, but if it works for your tiedown-point, shorter is better for security.There are a couple claims about the "dorable" rating on this lock, but the specifics aren't that impressive. I didn't destructively test this lock, but I can tell you based on my expertise as a Mechanical Engineer, that the Triangular bar does very little to help the strength of the lock (besides maybe wear down an angle grinder pad a little quicker due to the edge). A hacksaw will definitely eventually get through, larger bolt cutters can cut through. and any lock fails against an angle grinder. Bike thieves can carry several foot long bolt cutters on them hidden, and/or battery powered grinders. but to defend against that type of attack, you'd need to spend a lot more money and carry a lot more weight.The lock portion has a cover to protect it from moisture, which is nice, and it feels pretty solid. The whole assembly weighs 2 lb 5.5 oz.Overall, this is good, solid feeling. The length could be a problem for some, so really pay attention to your needs. It comes with extra keys.