This Internal Pipe Wrench Set features expandable knurled cams that provide an easy, internal grip on pipe nipples without marring, scratching or denting the pipe surface. The set includes 3/8 in., 1/2 in. and 3/4 in. pipe wrenches, which feature a durable steel construction for a long-lasting use. Requires standard or adjustable wrench for use. Covered by the Husky lifetime warranty.