NFL Shield Mid Size SpeedFlex Football Helmet. The ultimate NFL Mid Size SpeedFlex Football Helmet collectible, perfect NFL Mid Size Speed Football Helmets for autographs and collectors. Mid Size Speed Football Helmet with great graphics. Official NFL Mid Size SpeedFlex Football Helmet with official NFL team decal. Iconic SpeedFlex shell with a plastic SF-2BD-SW face mask. Internal padding and soft cup chinstrap includes a visor This is an affordable NFL football helmet for the true fan. Size: between Replica and Mini versions of NFL football helmets. Size: 10 (L), 6.25 (W), 7.5 (H) - (NOT FOR WEARING).