The Schwalbe Tube Extralight No.18 with Presta valve (Sclaverand) is ideal for wider tires - trekking bikes and cyclocross racers are the perfect recipients. The butyl rubber tube is extremely airtight and elastic. The high elasticity means the tube covers a wide range of tire sizes.
The Schwalbe No.18 fits the following tire sizes:
28-622 (700 x 28C) 30-622 (700 x 30C) 32-622 (700 x 32C) 37-622 (700 x 35C) 40-622 (700 x 38C) 42-622 (700 x 40C) 44-622 (700 x 42C) ;"