Ottsix 1.9" HALO WebWrap 2-Stage Foam Inserts feature a unique, flow through and waterproof 2 stage configuration. The Halo WebWrap uses a waterproof closed cell inner ring for exceptional side-hill control, with a unique web like waterproof outer ring that allows water to flow through the foam and provides an exceptional feel. Halo WebWrap foams are optimized for Ottsix KLR and KLR/M Tires, but can also be combined with a variety of similar size name brand 1.9 tires. Refer to the chart below to determine which Halo foam is right for your application.