The ultimate in safety, these tubes offer exceptional puncture resistance, excellent pressure maintenance and are easy to fit. Thanks to its uneven design, the Protek Max inner tube has a compression reaction in the event of piercing or nipping (the hole closes up naturally), whereas a classic inner tube has an extension reaction (balloon effect).The square shape is naturally positioned in the rim well and does not twist, unlike a completely tubular classic tube. Protek Max only needs to be inflated half as frequently as the standard Michelin Airstop.