The S-10 is a compact snapshot camera with a retractable housing for the Kodar f/9.5 35mm lens. Flash is provided by flashcubes and the film is advanced by the knob on the right-hand end of the body that also turns the flash cube to the next position. The camera has 1/40 of a second and 1/125 of a second shutter speeds and the lower of the two shutter speeds is only available when a flashcube is fitted, the fitting of a used cube is the recommended means of obtaining exposure in less than sunny conditions. The rather obvious shutter release also retracts when the lens housing is pushed home in the down position flush to the camera. The S-10 is one of the few Instamatics with an electronic shutter powered by two 1.55 volt EPX825 (S825PX, PX825, KA825, LR53, or BLR53) batteries. The battery cage will not release and it cannot be replace with the lens housing extended because of a contactor that contracts when the housing is depressed effectively turning of the camera. The shutter is somewhat difficult to release with no film and will not release with the back cover opened. The film activates the shutter via the spring post that enters a hole in the 126 film at each frame. The Instamatic S-10 was introduced in 1967 and discontinued in 1970. The camera uses the 126 cartridge film introduced by Kodak in 1963 to produce a 28 by 28mm picture size. The original manufacturers suggested list price in 1963 was $27.50. Some of the information here was gleaned from The Kodak Classics site.