Our single 3/32in. elevator door sheave is sized for hiding in set walls. It has sealed ball bearings for low friction. We recommend using 1/16' cable for actually rigging elevator doors, as the bend resistance is less than the rated 3/32' cable. These were originally designed for 'Galaxy Quest' (1999) to operate doors on the spaceship set. Every door opened differently; single slider, double slider from both sides, double slider from same side, triple slider, etc.