The 9817 Halo Helmet is a protective helmet designed for wear by individuals who have balance disabilities, head/skull injuries, or seizures who do not need full head coverage. A band of 5/8-inch foam surrounds the head at the forehead level. It extends down to the temporal area on each side of the head and to the occipital area at the back. The top has adjustable crisscross straps to help stabilize the helmet on the head. An adjustable chin strap is included. OPTIONS: 7640 Velcro Chin Strap, 3466 Reinforced Liner, 3467 Reinforced Seams, 3468 Foam Visor, 3469-U Quick Release Buckle Chin Strap Under Chin, 3470 Eyeglass Relief Area, 3472 Custom Strapping System, and 3460 Soft Foam Ear Coverings. SIZES: Extra extra small, extra small, small, medium, large, extra large, and extra extra large. DIMENSIONS: Large is for head 23 to 23.75 inches in circumference; medium is for head 21.5 to 22.25 inches in circumference; small is for head 20.75 to 21.5 inches in circumference; extra small is for head 19 to 19.75 inches in circumference; and extra extra small is for head 17.5 to 18.25 inches in circumference. COLOR: Casa tan, pink, or royal blue. These custom colors are available for an additional $26: light almond, baby blue, black, bright blue, forest green, silver/gray, maroon, orange, purple, red, teal, white, and yellow.