Michelin C4 ProTek Max 26x1.85-2.30 Self-Sealing Tube PrestaMichelin C4 ProTek Max 26x1.85-2.30 Self-Sealing Tube Presta. Thanks to its uneven design, the MICHELIN Protek Max 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 self plugging effect is increased by adding the sealant at the origin.086699288912