Keymod is clearly the better design. Picatinny is a male attachment system, in that the accessory to be attached uses a female attachment to clamp onto the exposed rails on the picatinny. Pin on Wood AR15 Furniture The keymod system utilizes a “keyhole” to index accessories and attach them directly to the rail. Keymod or m lok slots . Top 10 keymod to m lok adapter of 2020 on the market. They introduced this system to the market in 2014, and similar to the keymod, it allows a user to mount accessories directly. The accessory is correctly seated in the slot if the bottom of the accessory is flush. Buy, sell, and trade your firearms and gear. Since this test, interest in keymod has been reduced, but it is far from dead. I typically only mount a light, front sight, and maybe a foregrip, the rest of the time, i prefer to just hold on to the handguard. After the drop tests it solidified that keymod slots would not be able to hold up to the military’s desired standards