Although this 3-pulley system is useful for many pulling or lifting jobs, one of its most popular uses is as a calf puller. Attach the single block to an anchor point not more than two metres from the calf, then using calving chains or ropes on the calf's legs, connect the double-pulley block to the calf. The rope lock and release mechanism on the double-block is then easily and conveniently operated at the same time as checking the birth is progressing correctly. The Fast-Lock pulley system uses 7.2m of 10mm polyrope.