One set accommodates 1/8"-NPT PTF grease zerk fittings, M10x1, and fittings featuring a hex size of 3/8" (9.5mm) and 7/16" (11mm). The other set accommodates 1/4"-28 SAE, M8x1, and Zerk fittings featuring a hex size of 5/16" (7.85mm) and 3/8" (9.5mm).
