FC-681 Off-Camera E-TTL Flash Cable for Canon 580EX II, 550EX, 540EZ, 480EG, 430EX, 430EZ, 420EX, 420EZ, 380EX, 300EZ, 220EX. 10ft 3M coiled remote cord it support all functions of Canon EOS Camera, as well E-TTL functions of Canon flash sytem Cable Unstretched length: 0.6m Cable Max stretched length: 3.0m The UNC (Unified National Coarse Thread) of tripod socket is 1/4