Precision Reflex AR-15 SPR Straight Top Rail for Gen 3 Round Rifle Length Forearms Black. Rail connects to rifle receiver with 3 cross bolts and the front of the rail connects to the Gen II forearms top rail using to screws. Rail is 17.7in in length with an add elevation of .450in. Weights 10.0 Ounces Specifications for Precision Reflex AR-15 SPR Straight Top Rail For Gen II Round Rifle Length Forearms: Manufacturer: Precision Reflex Color: Black Finish: Hard Coat Anodized Fabric/Material: Aluminum Gun Rail: Picatinny Cant: 0 MOA Gun Make: AR Platform Gun Model: AR-15 Length: 17.7 in Width: 1.35 in Height: 0.45 in Weight: 10 oz Condition: New Package Contents: Precision Reflex AR-15 SPR Straight Top Rail for Gen II Round Rifle Length Forearms Precision Reflex 05-SPR-01: AR-15 SPR Straight Top Rail for Gen 3 Round Rifle Length Forearms Black