Master Lock American/Master Lock - (3) Keyed Alike Solid Steel, High Security, Hidden Shackle Padlocks, w/Bumpstop Technology A2010NKA-3

The outer shell is top notch steel, it is really heavy duty and has a nice weight/heft to it. But the locking mechanism & keys we're not smooth. It could have been the ones I was sent had poorly cut keys or the lock cylinder wasn't manufactured well. Initially when I took it out of the crushed box it arrived in (either UPS didn't handle it with care, of the sheer mass of the product & the shipping process banged up & crushed the box) the key wouldn't even turn. I had to fiddle with it for a while when it was brand new out of the box to even get the key to turn and the lock cylinder to come out only to find out it wouldn't fit only my shackle/hasps to secure my door.Given that the key and lock mechanism didn't slide out easily and smoothly and you pull the mechanism out as well as unlock it with the soft brass key, I think in the long run, you'll end up breaking the key and having this lock permanently locked on your shackles which would be expensive for a lock smith to remote if that happenedThis was a huge disappointment since I wanted a really secure lock to lock and guard my stuff & this would have met all my criteria in terms of high security, hard to cut, break or defeat, and heavy duty steel, covered shackle so bolt cutters cant be used.

Very nice lock, but it would not fit the latches on my 2018 Diamond Cargo trailer. Bent the latches closer together and it still would not lockUpdateThe ones that worked for me was the Master Lock 6271KA.

Other product reviews say this will beat Master Lock if someone tries to lockpick. Gives me extra sense of security after having my Chevy work van broken into after the thief probably just punched a large screwdriver into the keyway and simply turned the linkage to open door

I purchased 4 of these locks. They did not fit my application and tried to return. The vendor was absolutely awful. I needed to involve Amazon and threaten small claims action in order for them to accept the return of new locks in new packaging and refund my money.

These are a beast. Had to return because they would not fit my trailer. My bad for not measuring first. I had a puck lock that had a notched back and it fit. Did not realize that a flat back would not. Wish they had because they are very sturdy.

Los tenjo ya ase un ano y ni el agua ni la intemperie los a oxidado. Bale la pena comprarlos un poco carritos creo pero los vale al que le gusten la calidad ,durabilidad,ext no lo piensen .

These locks are great! I was looking for a more secure puck lock for my work van. Most are 5 pin and easily packable. This model is one of the best. It is a 6 pin lock, with changeable pins for rekey and it had a special bump stop feature. These lock are heavy and sturdy! Very happy with purchase. I use these on a set of "Slick-Lock" brand brackets on my van, fits perfect. Also the back is flush/flat for more security. Some puck lock backs are not flat which leaves a gap on one side.

Bought a travel trailer. Used these to secure the rear drop door of the garage area.Feel much more secure while away from the camper, and secured equipment.

Solid and strong