Double Sided Design Allows the Tool to Work on Both A/C and Main Drive Pulleys When Installing Stretch Belts on GM 5.3.L, 6.2L, and 6.6L Gas Engines. Double sided design allows the tool to work on both A/C and main drive pulleys when installing stretch belts on GM 5.3L, 6.2L, and 6.6L gas engines. The long tab is used on the A/C belt found on 2014 and newer GM trucks. The short tab can be used on the main drive belt found on 2019 and newer GM. Heat treated steel provides added strength. Black oxide finish.