Customized base mount for those helmets that come to a point at the center. Some of the known helmets that this mount works for are: Fox Dropframe Fox Proframe Fox Rampage iXS Xact Evo iXS Xult DH Kali Central Kask Defender Lazer Cage Kineticore Lazer G1 Lazer Sphere MIPS Lazer Strada Keneticore Leatt Gravity 4.0 Specialized Chamonix Troy Lee Designs D1 Troy Lee Designs D4