Esigned for the tough world of mountain biking and heavy commuting use great for touring with full suspension universal mtx type deck design accepts all topeak trunk bags 20lb carrying capacity tough 6061 t6 alloy construction hinged seat post clamp with alloy release lever integral bungee cord one size fits all seatposts shims includedweight 680gms three designs available for a perfect fit on various frames sizes e type for standard size frames44 v type for large frames44 a type