The K-Air Pressure Relief Valve is a must have for any inflatable craft allowing for proper inflation. Once the optimal PSI is reached the pressure relief valve will open releasing extra pressure that can otherwise damage inflatables. Simply attach the K-Air to the end of your pump and once you have reached optimal pressure you will hear the pressure relief valve kick in letting you know you are up to full pressure. No more guessing or stopping and checking with a gauge... it really is that easy! Even includes a standard car/bike tire valve which can be used with an air compressor.