Designed With A Removable Flap To Protect From Damage And Guard Against A Light A.d. From Your Gps. Elastic Arm Band For Comfort But Also Allows You To Mount The Gps On Your Sopmod Butt Stock For Your M4. Built With A Better Retention System Than Any Other Holder On The Market. Made With High Quality Mil-Spec Materials. Made To Hold The Garmin Foretrex 401 Gps And The Garmin Foretrex 101 Gps. Lifetime Warranty, Made In The U.s.a, Berry Compliant