Miami Dolphins Throwback Mini Speed Football Helmet. The ultimate mini speed football helmet collectible, perfect mini speed football helmets for autographs and collectors. Mini Speed Football Helmet with great graphics. Official Mini Speed Football Helmet with official team decal. ABS plastic Mini Speed Football Helmet shells with plastic facemask. Realistic interior foam padding, vinyl-leather chin strap. This is an affordable football helmet for the true fan. Size: 1/2 scale versions of football helmets. Size: 6"(L), 4½"(W), 5"(H) - (NOT FOR WEARING).