Original HK manufacture (not Airsoft!) sight sets for the HK416/417. However, these will fit any standard picatinny or 20mm rail. The rear sight has the standard HK rotating drum with four different sized apertures - as used on the MP5, HK33, G3, etc. Lightly used condition. These sets retail for over $300 in the US. Call our credit card sales hotline to buy this item now with your credit or debit card - 024 7637 3581.