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 application. Clamp prongs (4) are cork lined to provide a cushioned, slip resistant hold. Thread fitted actuating joints. The screw adjustment allows for precise pressure when gripping glass objects, to avoid potential breakage. Swivel between Clamp and Bosshead. The clamp includes a high strength alloy Boss Head for securing the clamp to a frame or other apparatus. Dimensions:-. Maximum clamp opening is 10.5cm. Clamp accepts apparatus measuring up to 8.5 cm. Boss accommodates up to 18mm diameter rod. Caution:. Due to the cork lining it is not recommended that the prongs of the clamp are placed in direct heat.