CTA Tools 2450 Plastigage - 2-Piece Set is designed to measure clearances of the engine rod and main bearings without expensive micrometers. Two (2) gauges are included in this set. They make choosing the proper size of replacement bearing inserts easy and worry-free. The set features 2 sizes: 0.001-inch to 0.003-inch and 0.002-inch - 0.006-inch (0.025 - 0.08-millimeter and 0.05 - 0.15-millimeter) to cover all auto engines. The gauges feature measurements conveniently printed on the envelopes, easy color-coding, and is built to be resilient and flexible. The heavy-duty construction allows for strength and durability. Whether tuning up your '68 Corvette or changing the oil on a John Deere tractor, CTA can supply you with the tools needed to do the job.