The Pop Out Rail Adapter Kit works directly with our M-LOK helmet rails. Precision machined from aerospace grade aluminum they are rugged and robust. The pop out feature allows the user to "pop" the headset off the ears for venting and donning. They allow the user to seamlessly integrate hearing protection headsets or communications systems (headset guide) directly onto helmet rails. This eliminates the need for an uncomfortable strap underneath the helmet that eventually creates hotspots and headaches. *Important* Every head shape is different. You will need to bend the wires to fit your head shape in order to get the correct seal and pressure with the pop out feature. Ensure to watch this video on the install! https://www.youtube.com/watch?v=AsvlgAqee_g