This is our large high quality heavy duty, made in the U.S. ramp style flow control valve that will accommodate from 5/16" to 1/2" outside diameter thick wall rubber, silicone or vinyl tubing. It works perfectly on any of our 5/16" silicone tubing selections. Valve will accurately control fluid flow in flexible tubing from zero to full flow with the use of the grooved thumb control wheel for adjustment. Small gear teeth on each end of the center axle shaft of the roller wheel engage the matching teeth in the slotted channels on each side of the body for precision actuation without slippage. All our ramp clamps and ball style flow control valves are made in the U.S.
This clamp is specifically for the heavy gauge, or thicker wall silicone tubing we now offer as well. The best way to apply the clamp to the tubing is to pop the roller wheel out of the end of the channel and then lay the tubing into the channel at the position you desire. Then press the roller back into the end of the channel until you hear it snap into place and it will then roll up and down the channel and apply pressure and close or open the tube.