The Piston 3 clamps onto your valve in the usual way, but is there a better way? One that avoids pinched fingers? by Paul Horta-Hopkins · 09/11/2016 The Piston 3 clamps onto your valve in the usual way, but is there a better way? One that avoids pinched fingers? Share this:FacebookTwitterWhatsAppPinterestTumblrLinkedInPocketEmailRedditLike this:Like Loading...