The Food Warmer Accessories by Hatco: Casters, 3 in diameter, locking (adds 4-1/4 in to height of unit) ( Hatco - HDW-CASTER-3 ) - To enable mobility, the Hatco HDW-CASTER-3 locking casters can be attached to HDW-1, HDW-2, and HDW-3 drawer warmers....