Cardinal HealthTM Dravon Plastic Occluding Tube Clamp (Hemostat) When it comes to safe and reliable occluding, you can depend on Dravon's "True Blue" A-Clamp. Smooth jaws are featured that allow for occluding 1-mm to 8-mm tubing without damage. A special nylon formulation makes the A-Clamp strong yet lightweight.