Specifications:- Overall Dimension(LxWxH): 11 13/16"" x 8 7/8"" x 6 11/16"" (30 x 22.5 x 17 cm)- Size: M- Fits Head Circumference: 22 7/16"" to 22 13/16"" (57 to 58 cm)- Material: Abs, Eps- Net Weight: 2.43 Lbs (1.1 kg). Package Contents:- 1x Helmet- 1x Epe Bag- 1x Carrying Bag. Notice: - Before purchasing, please measure your head's circumference to determine which size is suitable for you.- Make sure the measuring tape lays flat against your head but doesn't pinch. It should be level all the way around.