Alien headset holder. The holder is designed to hold a steele series arctis pro wireless headset with a head band of 42mm wide. The top of the alien head is measured at 43mm wide. if you need to adjust it you will need the headband width and follow the formula “ X *235/43” X is the width of the headband you want. Each of the eyes fit in to a specific eye socket so make sure you pay attention to which one you are inserting. I hope you enjoy it and let me know if you need assistance with measuring.