NCStar's Gen2 AR15 Riser raises your Picatinny rail platform by .75" which aids in getting low profile optic mounts to a more comfortable cheekrest height and shooting position. It mounts onto the Picatinny rail of your AR15/M4 receiver by a locking Quick Release, which allows you to quickly attach and remove your optics and maintain zero. The Gen2 model has an updated shape, a locking Quick Release mount with shorter lever, and is lighter than the previous version. A see-through channel below the rail keeps the mount lighter, and allows you to use factory iron sights.