GSI Super Quality Remote Shutter for Canon 40D, 7D, 10D, 3, D2000, 1Ds, 5D, 1D Mark II, D30, 20D, 1V, 1D, 1Ds Mark II, D60, 30D, 1Ds mark III, 1D mark III, D70S, D80 Cameras, Functions Exactly as the Canon RS-80N3, Provides Great Photography Flexibility. Prevents Camera shaking in Close-Up Macro Photography, and Super Telephoto Shots Absolutely a Must for Night Shooting or for Difficult Approach-to Pictures Two-stage release button - halfway pressing for auto focus and complete pressing for shutter release Button locking for bulb exposure by pressing completely and sliding forward - easy for long exposure and continuous shooting Support synchro-cable to control 2 cameras simultaneously,