This very early key was the largest and heaviest I've made so far, I always wanted a really large key and had to get it out of my system, it had really big bearings 22mm, mounted in 22mm water pipe housings, a really long arm that was fitted with a tension spring with big brass arches it was a giant key, in truth a bit to heavy, I used it a few times but reluctantly decided to sell it to recover the brass costs. nice key.