I just noticed that. It can't be a very heavy duty puller if all you have to turn the forcing screw is a t-handle. I've use BIG breaker bars on the end of my puller (Craftsmen version of the one I posted above) without issue (press-fit crank pulleys on American cars are a PITA). I like the concept of the lockout feature for the arms but I wonder how effective it really is especially as the load increases.