Home Products ENGINE SERIES KT-6109K KT-6109K KT-6109K VACUUM CUP VALVE GRINDER For hand grinding flat head, unslotted valves. Synthetic rubber vacuum cups are resistant to oil, grease, gasoline and are replaceable. Cup diameters: 5/8", 13/16", 1-1/8", 1-3/8". 1673764