The 1557AA is a punch sleeve component designed for use with the Greenlee Intelli-PUNCH battery-hydraulic knockout driver system. This sleeve measures 1-1/8 inches by 3 inches and is specifically engineered for punching operations on mild steel conduit and pipe ranging from 3-1/2 inches to 6 inches in diameter (102.7 mm to 161.9 mm). The 1557AA sleeve is paired with a 3/4-inch by 5.38-inch draw stud (model 2113B) and requires a 1-3/8-inch diameter pilot hole (34.6 mm) for proper operation. This accessory is essential for achieving clean, precise knockout holes in larger diameter mild steel applications, providing reliable performance as part of the complete Intelli-PUNCH system.