Crain 968 Floor Following Power Groover tracks in the seamline to cut a trapezoidal groove for welding. It maintains consistent grooving depth even when floors are not level, up to 1/8" of variation over one foot of seamline. The floor following wheel rides on the floor to raise or lower the blade in response to variation. A spring-loaded floor following a dust shroud improves dust control. Includes a 12 tooth 130mm diameter x 3.3 mm wide carbide-tipped blade (No. 971), and carrying case. Diamond grit blade for metal-impregnated safety floors is sold separately (No. 972). 110VAC 9A No-load RPM 12,000. Max. groove depth 3.5mm. Net weight: 20.5 lbs. Crain 968 Floor Following Power Groover Parts, Instruction Manual.