Avon B7Inflation / Deflation Valves. The B7 is identical to the A7 in itsinner workings. It offers all the advantages of the A7 but provides alower and a more snag free design. Its rounded mushroom shaped cap fitsclose to the chamber. It clamps directly to the chamber material so itdoes not require a mounting boot to be glued in. Requires no routinemaintenance. Color is gray.