Sony’s mirrorless cameras have a special coating on their sensor. The standard Sensor Gel Stick cannot be used with those sensors. However, any camera from other manufacturers such as Nikon with a Sony sensor and Sony cameras (DSLT and DSLR) that are not mirrorless can use the standard gel stick. This includes Sony SLT cameras such as the A65, A77 and A99. The current list of Sony cameras that must use the special Sony-specific gel stick is: Sony A7R, Sony A7, Sony A7S, Sony A5000, Sony A6000, Sony NEX-7, Sony NEX-6, Sony NEX-5 (all models), Sony NEX-3 (all models).