This is a Marlin No 336 308 444 1894 1895 39 39A 55 ORIGINAL Folding Rear Sight Assy Height 0.50 folding flat sight that fits on the Marlin No 336 base (picture 3). This folding flat-topped sight works for all Winchester and 35 Remington rifles, and is especially good on 1894 Winchester 30-30 caliber 1894 Sporting rifles. Elevator part# st173