We had seen a prototype for an HK416 handguard at the Strike Industries SHOT Show Booth back in 2014. They have now introduced the Crux, which they are touting as the lightest option for the popular firearm, which is also compatible "civilian" MR556 variant as well as the .22LR clone. Clearly the KeyMod attachement system is one key component to bringing down the weight with slots at the 3,6, and 9 position. The design offers drop-in installation and a Picatinny top rail for optics. They even released a snazzy video promoting their aptly named product, which you will find below.