Simson Big Mouth bidon The Simson Big Mouth bidon is handy while cycling or exercising. The closable pull spout has an air valve that opens by squeezing the bottle and closes automatically. This makes the bidon easy to use with one hand, which is very handy while cycling! With the extra large big mouth opening you can quickly and easily restore your fluid balance. Specifications: Color: gray/black Material: plastic Content: 550 ml