Schwalbe Air Plus AV19AP 29 x 1.75" - 29 x 2.40" Schrader Valve 40mmAIR PLUS. THE TUBE WITH THE BEST AIR RETENTION. A real plus for your range! The new Schwalbe Air Plus. Ideal for e Bikes and cargo bikes! First Plus: Higher air retention: Thanks to the high proportion of pure butyl rubber, the Schwalbe Air Plus tube retains air much longer. This means less inflating is required. Second Plus: More puncture protection: With around 70% greater wall thickness, the Schwalbe Air Plus is particularly robust and so it's well