Hera IRS M-LOK Rail-System The Hera Arms IRS-MLOK is a modern designed Handguard made from high-quality aluminium and is build to handle the hardest use and abuse of tactical and competitive shooting. The IRS-MLOK is CNC milled from aluminium alloy and hard coated anodized for added strength. Length of 12". The IRS comes with his own barrel nut where the Handguard is clamp mounted with 3 screws for additional strength. The anti-turn millings prevent turning even at the hardest use.