Versatile polymer triple rail mounting system is available as a single 3" Picatinny rail (TRM), two 2.5", 45 Picatinny rails (TRM2), or combined to provide a triple rail mount (TRM3). Use all 3 rails on lower handguards for grip with easy thumb access to light & laser on side rails or use 3" rail on bottom & 2.5" rails on top.Allows easy tactical light operation while using a vertical grip and light mountRails can be used independently of each other45 rails will not interfere with iron sightsMounts on the upper and lower vent holes of most existing standard handguardsConstructed of high-density polymerPart #: TRM3TRM3: Triple Rail System (TRM and TRM2 combined). Fits: M16/AR15/M4Number of Rails: 3Made of: PolymerWeight (oz.): 3Width (in.): 2.75"Length (in.): 3"Height (in.): 1.5"