Ribtect SFI Kids Chest ProtectorsSFI Approved Spec 20. 1 WKA and IKF Approved Many slide tests performed at the Delphi facility Chest protector comes in two sizes, size SM1 (ages 5 8) and SM2 (ages 9 12). Chest protector can be worn alone OR with any brand of rib protector Designed for maximum protection and comfort Lightweight Non Bulky Two layers of vacuum formed polypropylene plastic Strong, heavy duty buckles Patent #D532,938S