Seattle Seahawks Full Size Authentic Revolution Speed NFL Helmet by Riddell. This full size Seahawks helmet is designed with extended mandible (jaw area) protection, a steel polyvinyl-coated face mask, chin strap, increased padding, an integrated facemask attachment system and elliptical air vents. NFL Team name on back bumper (except Chiefs, Steelers and Giants). The officially licensed Seattle Seahawks helmet is great for autographs and features Seahawks team logo decals on both sides. The striking shape of the future. NFL Seahawks Authentic Revolution Speed helmet size is 13.5"(L) x 9.75"(W) x 10.25"(H). NFL Seattle Seahawks Full Size Helmet. .