This is a HK Diopter sight for the HK MP5, MP5K, SP5, SP5K & all clones that are within factory spec. These are used but in very good and functional condition. They come with the sight base and drum with detent ball, oval washer , serrated lock washer, and screw to mount the sight to the weldment on the receiver. ( ATTN: the detent ball is in the sight base as it is has grease retaining it in the hole, all were checked for function before being bagged. This is what you need to make that SBR'd HK correct instead of the pistol sight .
as is no warranty