Protect yourself from the elements with a Propper® Boonie. Sewn to military specification MIL-H-44105B, the Boonie hat includes vent holes on either side to allow for air circulation Our eBay Store Propper Boonie – OCP 50/50 NYCO Protect yourself from the elements with a Propper® Boonie. Sewn to military specification MIL-H-44105B, the Boonie hat includes vent holes on either side to allow for air circulation. Use the adjustable chin strap for a secure fit. 50% nylon / 50% cotton ripstop Sewn to military specification MIL-H-44105B Metal vent holes Adjustable chin strap Imported