3 finger Vinyl coated Extension Lab Clamp on Swivel Bosshead 8.5cm 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 it won't rust!Clamp constructed of powder coated high grade Zinc die cast construction. High grade nontoxic. powder coating. Non-ferrous rust free & long lasting use for any laboratory applicationThe 3 fingers are coated in vinyl for higher temperature applications and to provide a strong slip-free hold.Complete metal constructions thread fitted actuating jointsClamp is attached to swivel bosshead that fits rods measuring up to 18mm in diameterDimensions:-Clamp accepts apparatus measuring up to 8.5cm.Maximum clamp opening is 8.5cm14cm Stainless Steel Connecting Rod10mm diameter connecting rodSwivel bosshead fits rods measuring up to 18mm in diameterThe screw adjustment allows for precise pressure when gripping glass objects to avoid potential breakage.The round extension arm allows the clamp to be rotated 360 degrees as well as varying the distance from the supported apparatus.