The torque wrench is for R410A and R32 refrigerants. 17mm is for 1/4” connector, 22mm is for 3/8” connector, 26mm is for 1/2” connector and 29mm is for 5/8” connector. Normally, the hexagonal size of connector is little smaller. Please use the caliper to check your connector. Maybe the size is much smaller than nominal size. For fixed open ended wrench, the size of wrench is little bigger. If you put them together, you will find it is loosen. However, we use adjustable wrench head. So it can be fit the connector closely.