These dura clamp tubing flow valves can be easily operated with one hand, and will not rust or corrode. Available in mini, maxi or medium sizes, select the clamps that best suit your needs. Mini dura clamp accepts tubing O.D. up to 6 mm, maxi dura clamps accepts tubing O.D. up to 19 mm, and medium dura clamp accepts tubing O.D. between 3 mm and 12 mm. Autoclavable.