The 9mm Self-Stick-Valve is the industry standard for all inflation valves. Will work on 99.9% of all kites in production. Available in one way or two way valves. The 9mm Self-Stick-Valve 2 way valve (inflate/deflate) will fit most newer kites as a inflate valve and is used on older systems as a inflate/deflate valve. One way valve lets air enter while pumping but stops air from going out. Simply squeeze valve to let air out. 1-way flap can be cut out to create a 2-way valve.