Schwalbe tubes are designed & manufactured to retain air pressure considerably longer than their competitors. Not only is each individual tube inflated & inserted into a mould to ensure that there is even wall thickness & excellent air retention, they are also stored under pressure for 24hrs to test air retention.

Used on some wheel chairs

Applicable Tyre Sizes:
44-484 - 22 x 1 1/2
37-489 - 22 x 1 3/8NL
28-490 - 550 x 28a
37-490 - 22 x 1 3/8 - 550 x 35a
37-501 - 22 x 1 3/8