Model accepts optional 4" (102 mm) diameter Type 27 reinforced Depressed Center Wheels, with 3/8" (10 mm) center hole; wheel width of 1/8" to 1/4" (3 mm to 6 mm). Dual-wick lubrication system saturates gears with oil for increased performance, extended life and reduced downtime. Adjustable wheel guard provides maximum operator protection. Models include aluminum right angle housing. Each model includes side handle for left or right-hand use.