This UTG Free Float Carbine Quad Rail Unit for M4 is built from high quality aluminum and is extremely easy to install. This rail system is designed to work in place of your standard M4 hand guards; simply remove your plastic hand guards, put the rail system in place, and tighten down the screws to secure the RIS. No special tools are needed, the operation to install this RIS can be done in seconds. Included with this RIS are 18 sectional rail cover panels designed to protect the rails that aren't in use and protect the users hands from being cut while using the gun. UTG has always been dedicated to producing high quality products that are user friendly and easy to install, and this free float RIS is a great example of their mission statement.