Does not require drilling or tapping to create a solid mount to the receiver. Mounts the sight closer to the shooter's eye, giving the shooter a sight picture similar GI type rifles. Increases the sighting radius by 10" over the stock factory sight mounted in front of the receiver. Returns to zero after removal. Uses incremental windage adjustment with rugged detent locking. SKS sights mount solidly to the receiver and are not affected by the movement of the receiver cover. TS100 comes standard with flip dual short/long range (.062) apertures. The steel sight frame is constructed of high strength steel and hard coat steel components. The steel sight frame is constructed of high strength steel components. Patented design. TS195 Sight Adjusting Tool SKS (not included but also available on Amazon) Also available Amazon for the SKS is the TS200 the TS200 has both elevation and Windage in the rear sight. Both the TS100 and TS200 have advantages depending on the shooter preference. for install some SKS models have the Latch Pin is brazed in place. This may make more difficult to remove, it can be done at home if handy, but some people prefer a gunsmith in some cases.