Buy Caps and Hats Safari Fishing Hat with Neckflap Boonie Mens Grey Camouflage Safari Hat and Bumper Sticker by Buy Caps and Hats. Adjustable chin strap. Neck flag for more sun/wind protection. Air vents to help keep head cooler in warm/hot conditions. Large brim/rim to protect ears, head and face from elements. Sizes for these hats are approximately: SMALL- 19 to 22 Inches, MEDIUM- 20 to 23 Inches, LARGE- 20 to 24 Inches, X-LARGE- 21 to 25 Inches.