Product size:49*11CMMaterial: Main material is low-carbon steel, 1000D nylon, elastic band for easy adjustment.Comfortable: Soft padded nylon fabric on both sides can protect a comfort and good protection.Advantage: Steel mesh design can't block the sound, Allows you to quickly communicate combat commands.One Size Fit All: One size with elestic band, fit for most FAST tactical helmets. NOTE:THERE MAY BE SLIGHT ERRORS IN MANUAL MEASUREMENT, PLEASE REFER TO THE ACTUAL PRODUCT.