Lancer LCH5 Extra Long 15 Inch Cooling Slot with 2 inch sight rail, has an overall length of 16.25 inches and is designed to be used with rifles with a barrel length of at least 18 inches. The sight rail is permanently attached and should not be removed. The weight of the handguard, including proprietary barrel nut is 12.5oz and the handguard is a free float design comprising of a custom octagon shaped carbon fiber handguard tube connected to the upper receiver with a 7075-T6 aluminum upper receiver extension. Cooling slots have been provided to manage barrel temperature and allow the connection of accessory rails, there are also slots at six o'clock for an accessory rail and holes for sling swivel stud so a bi-pod can be attached. Being of free float design the installation requires the removal of the rifle's barrel and specialized knowledge in AR rifle disassembly and assembly.