The A40 Tr Headset Can Be Adapted To Any Environment By Adding Astro Mod Kits. For Loud Pro Tournaments, You Can Transform The A40 Tr From An Open-Back To A Closed-Back Noise-Cancelling Headset By Swapping Mod Kit Components Including Noise-Cancelling Ear Cushions, Voice Isolating Mic, Closed Back Speaker Tags And A Padded Headband. The A40 Tr Mod Provides Premium Comfort For Users, Allowing For Extended Campaigns And Grueling Multiplayer Battles. *Please Note: A40 Tr Mod Kits Are Only Compatible With A40 Tr Headsets And Not Any Other Headsets. The A40 Tr Headset Is Not Included In The Purchase Of A Mod Kit.