Cork Lined Clamp with swivel Bosshead 10.5cm maximum clamp opening.Suitable for beakers Erlenmeyer flasks test-tubes boiling flasks and burettes. Chosen for its quality: made from a strong alloy not iron so won't rust!Clamp constructed of powder coated high grade zinc alloy. High grade nontoxic. powder coating. Non-ferrous rust free & long lasting use for any laboratory applicationClamp prongs (4) are cork lined to provide a cushioned slip resistant holdThread fitted actuating jointsThe screw adjustment allows for precise pressure when gripping glass objects to avoid potential breakage. Swivel between Clamp and BossheadThe clamp includes a high strength alloy Boss Head for securing the clamp to a frame or other apparatus.Dimensions:-Maximum clamp opening is 10.5cmClamp accepts apparatus measuring up to 8.5 cmBoss accommodates up to 18mm diameter rodCaution:Due to the cork lining it is not recommended that the prongs of the clamp are placed in direct heat.