A valve set includes a valve body which includes a central hole and multiple passages are located around the central hole. A tubular portion extends from the valve body a flexible plate has an insertion inserted into the central hole of the valve body and the flexible plate seals the passages from an underside of the valve body. A core member is securely engaged with the tubular portion has an inlet tube. Multiple releasing probes extend from an underside thereof. A spring is mounted to the inlet tube and biased between a shoulder on the inlet tube and an inner surface of the valve body. A bottom cap is connected to the underside of the valve body. Air is introduced into the valve set via the inlet tube and released by pushing the core member and the releasing probes push the flexible plate away from the passages.