The frame of this lock is made from solid brass, very impressive construction for a lock in this price range, and has a steel shackle. Now the steel here is not just a sticker, but actual steel!
The steel shackle is not weak. I have managed to break a half inch chain with the shackle, but it was a hard job. The shackle does flex with enough force, so it is not as good as a stong solid piece of steel, but the steel on Monoblocks is far better than other locks. This lock comes in many sizes, and you can recommend the range after deciding what lock will fit where.
To change the key, with normal high security locks you have to completely remove the cylinder and key, and it is then possible to see how far wrong you have gone. With the Abus, you just turn the cylinder after removing the keys, and it is easy to get the new key in. This is a huge benefit if you have to shut a gate, or lock something quickly.
This is a great lock, and does just what it says, at a reasonable price. It is not indestructible, but it is far better than most padlocks, and if you have something to protect, you deserve to keep it for life.