This standard specifies the type, basic parameters, main dimensions, technical requirements, test methods, inspection rules, marking, packaging and storage of GIICL and GIICLZ drum gear couplings. This standard is applicable to GⅡCL type and GⅡCLZ type drum gear couplings that connect two horizontal coaxial transmission shaft systems and have a certain angular compensation performance for the relative offset of the two axes. The working environment temperature is -20-+80℃. The nominal torque is 0.4-4500 kN·m.