The Topeak Elementa Seatbag is an ultra compact saddle bag that can be easily hidden under your seat. It features a hook and loop fastening strap to securely carry an inner tube and tyre levers, ensuring a safe ride. The bag has built-in anti-slip fabric for added security during mounting.There are three sizes available: XS, S, and M. The capacity of the bag is 0.2L for XS, 0.3L for S, and 0.5L for M. The bag is made from durable materials including 500D Polyester, 1680D Polyester, aluminum rings, and a PU coating zipper.The XS size is compatible with inner tubes up to 700 x 28c and includes space for 2 tyre levers. The S and M sizes are compatible with inner tubes up to 29" x 1.75"-2.5" and also have space for 2 tyre levers. The M size additionally has room for a mini tool or CO2 cartridge.The bag attaches to the saddle rails using a hook and loop fastening strap, specifically designed as part of the Rail Wing System. The mount is secure and reliable.The dimensions of the bag are as follows: 10.5cm x 7cm x 2.7cm for XS, 10.5cm x 7cm x 5.5cm for S, and 13.5cm x 7.5cm x 5.5cm for M.The weight of the bag varies depending on the size; 42g for XS, 47g for S, and 54g for M.