Magpul MBUS Pro LR Adjustable Folding Rear Sight The MBUS Pro (Magpul® Back-Up Sight) is a corrosion-resistant all-steel back-up sighting solution that delivers maximum functionality and strength with minimum bulk at a price that’s even smaller than its size.  The new MBUS Pro LR capitalizes on the low profile and sleek styling of the original MBUS Pro, while adding the additional feature of an elevation adjustment wheel to accurately engage targets at variable distances. With its all steel construction, this is the sighting solution that delivers no-tool adjustments, maximum strength, corrosion resistance, and functionality in a compact package. Positive detents keep the MBUS Pro LR at standard AR sight height when deployed and so low when stowed that you will hardly notice them. Made in the USA. All steel construction Windage adjustable with low-profile knob Positive detents in both the up and down positions Elevation adjustment wheel for 200-600 meter distances