so sad,, they tried to get mine once. I had an 11mm U shackle. I think it was Bell. they used a cordless grinder and almost got thru it but I guess their battery died. I got a top rated 13mm U lock $54 the next day. it won't stop a pro but 90% of all scum cant touch it. but sometimes they throw dirt in the tank. next i want a lock cap. I think a gy6 will fit