If you are having a hard time deciding which rail system to use on your airsoft gun, ORGA Airsoft got this video to discuss the differences between these two rails systems... "Keymod / M-LOK edition, which explains the rail system that is indispensable for dressing up and attaching accessory parts for all air guns such as electric guns! Keyholes and rectangular holes in the hand guards of airsoft rifles such as M4 and AR-15. This is not just a hole for weight reduction and heat dissipation! I will explain about Keymod and M-LOK, which two firearm makers struggled to create a new rail system. Accessory parts that can utilize the rail system are in stock!"