Check the listing for details. Forward Controls Design MCF-A MLOK Handguard Panel - M-LOK Rail Cover 2 Slots. Color: Black, Condition: New. Listed at 37.95 USD. Specifications:Width: 0.600"Thickness: 0.152"Length: 3.2" (Covers 3 MLOK slots)Weight: .054 oz. per panelTorque Value: 17 in/lb.1/8 Allen key required for installation (not included)Includes:1x Cover Panel2x Mounting Screws2x M-LOK NutsThe idea of using aluminum covers over aluminum hand guards must seem strange. MCF-A doesn't simply insulate, but also dissipates heat generated by a hot barrel. MCF-A is slightly thicker than the G10 version it replaces. MCF-A has greater surface area from the rows of dimples, and its through holes that were designed as drain holes, now function as vents. Combined, these features make MCF-A behave like a radiator. These are the testing results: With strings of rounds fired, MCF-A heats up more slowly, and cools down much faster than the G10 variant.Sitting under direct Texas sun, then brought into 10 to 20 degrees cooler environments, G10 panel performs slightly better, but not appreciably so, with only 2 to 3 degrees of difference between the aluminum and G10 versions after a 5 minutes, and 10 minutes cool down.