Precision Reflex PRi AR15 / M16 Top Rail Riser 2 Hole Black. The full 1913 rail is has overall length of 6.25in with 3in of overhang. The riser weighs 3.3 ounces. The aluminum rail lifts the mounting surface up .450in and allows the extension to the front or rear. Specifications for Precision Reflex PRi AR15 / M16 Top Rail Riser w/ 2 Hole: Manufacturer: Precision Reflex Color: Black Finish: Hard Coat Anodized Fabric/Material: Aluminum Gun Make: AR Platform Gun Model: AR-15 Length: 6.25 in Width: 1.35 in Height: 0.45 in Weight: 3.3 oz Condition: New Gun Rail: Picatinny Package Contents: Precision Reflex PRi AR15 / M16 Top Rail Riser w/ 2 Hole Precision Reflex 05-0062: PRi AR15 / M16 Top Rail Riser 2 Hole Black