If you are looking for a tire with the longest possible life, Continental Ruban may be the right one. The central pattern provides low rolling resistance and high mileage. It is also great for electric bicycles. ShieldWall version with a folding foot and the option of a tubeless system.SL version = Silver Line, with silver labels on the side of the tire.Size: 29x2.3" / 58-622 Series: Performance TPI: 3/180 Shoe: kevlar / folding Compound: PureGrip Recommended pressure: 40-55 PSI ShieldWall System - cross-woven nylon fabric in sidewall adds excellent puncture or cut resistance Tubeless Ready - new foot and sidewalls = simple and perfectly sealed tubeless system