NcSTAR GEN2 AR15 3/4in Riser with Locking QR Mount. Helps with getting low profile optic mounts to a more comfortable cheek rest height and shooting position.GEN2 model has a new updated shape next generation Locking Quick Release mount with shorter lever and is lighter than the previous version.Mounts via a Locking Quick Release mount onto your Picatinny rail of your AR15/M4 receiver. You can quickly attach and remove your optic from your receiver and maintain your zero.There is a see through channel below the rail to keep the mount lighter and for some firearm types it may allow you to use some factory iron sights.Length: 5.3"Weight: 4.2 oz Specifications for NcSTAR Gen2 AR15 Riser w/Locking QR Mount: Manufacturer: NcSTAR Color: Black Gun Model: AR-15 Length: 5.3 in Height: 0.75 in Weight: 4.2 oz Mount Type: Picatinny Gun Rail: Picatinny Features of NcSTAR Gen2 AR15 Riser w/Locking QR Mount: GEN2 model has a new updated shape next generation Locking Quick Release mount with shorter lever and is lighter than the previous version Mounts via a Locking Quick Release mount onto your Picatinny rail of your AR15/M4 receiver You can quickly attach and remove your optic from your receiver and maintain your zero There is a see through channel below the rail to keep the mount lighter and for some firearm types it may allow you to use some factory iron sights Rail Length: 5.3" Black Anodized Aluminum construction. Package Contents: NcSTAR Gen2 AR15 Riser w/Locking QR Mount NcSTAR MARFQV2: GEN2 AR15 3/4in Riser with Locking QR Mount