The right size flash for the A6000, A6400,and the A6500, especially if you don't use the kit lens. All the other lenses make the built-in flash unusable by casting a shadow on the subject. I see why the A6600 does not have the built-in flash. Neither the camera nor flash have enough battery power for a day's shooting in my case about 600 shots. So, expect to bring a couple of extra AA batteries. Also, a big plus is it's diminutive size, the balance is perfect for these small cameras.