*small in size & light in weight and easy installation and maintenance. It can be mounted wherever needed. *simple, compact structure, quick 90íp degree on-off operation. *disc has two-way bearing, perfect seal, without leakage under the pressure test. *flow curve tending to straight-line. Excellent regulation performance. *various kinds of materials, applicable to different medium. *strong wash and brush resistance, and can fit to bad working condition. *center plate structure, small torque of open and close. *long service life. Standing the test of ten thousands of opening and closing operation. *can be used in cutting off and regulating medium *wide selection of materials, applicable for various medium Wooden box