Caster Kits come in two styles, one with four swivel casters, and the other with two swivel and two straight casters (shown). 

The set with four swivels is handy for manipulating your lathe around a tight shop.  The set with two straight and two swivel is better suited when you have an open shop or want to move longer distances, like down a hallway or out onto the driveway.  The straight casters help the lathe track better when going the distance.

In any case, extreme caution needs to be taken when moving a lathe on sloped surfaces. Robust lathes are heavy, and they can quickly get away from you when there is an opportunity to roll.

All caster kits come with a compact screw jack for lifting the lathe.  There is a bracket on the jack that fits into a notch on the leg assembly to keep it from slipping. 

The jack lets you get the casters on and off the lathe in tight spaces.

The Sweet 16 and Liberty use a different lever style jack.