NCAA Full Size Authentic Revolution Speed NFL Helmet by Riddell. This full size helmet is designed with extended mandible (jaw area) protection, a steel polyvinyl-coated helmet face guard, chin strap, increased padding, an integrated helmet face guard attachment system and elliptical air vents. The officially licensed helmet is great for autographs and features team logo decals. The striking shape of the future. NCAA Authentic Revolution Speed helmet size is 13.5(L) x 9.75(W) x 10.25(H).