Want to spiff up your tired old M4A1 Carbine? This rail system fits most carbine length M4 and M16 style airsoft AEGs. It is also compatible with the KWA LM4 gas rifles. Now you can throw on an assortment of lasers, flashlights, red dots and foregrips to your trusty rifle. This is a very nice metal rail system for any budget and should fit most guns. With any custom install, if it's a little loose, and it shouldn't be, you can always use a little electrical tape to keep any rattles down to a minimum. Easy and simple installation on standard M4 carbines with basic tools. We highly recommend this for M4 airsoft guns we carry.