Specially designed for separating quick-connect fittings on heater lines of 1999-2004 Chevy and GMC C/K trucks. Tool snaps around the hose and simultaneously depresses the locking tabs to disengage the fittings APPLICATION: C/K TRUCK The 0.75 inch (3/4") heater lines coming from the I.P. have quick connect style fittings. The access is very limited and the connectors have four tangs to depress at the same time. Slide J-43181 disconnect tool over the heater line. Clamp tool over line. Then press tool into the connector to release.