27mm / 1 1/16" six point 3 in deep socket with short extension just the right length to fit into the front pulleys and clear the radiator on most early 6 clyinder, small V8 and diesel engines from the early 1960's up to 1985
Deluxe version with pressure gauge designed by Kent Full, 20 20-minute videos, drain and fill instructions included. Please read the important note on the revision made on 3/3/20.