Robust, versatile, reliable - our clamps are ideal for working with a wide range of different stone materials. SECURE AND ADJUSTABLE - Our products come with self-locking nuts and adjustable opening width to ensure a secure grip without damaging the stone. Damage-Free Grip - The non-slip thread design of our product ensures a tight grip without any risk of damage to the gemstone. High-Quality Materials - Our products are made of high-quality polyurethane and alloy steel, ensuring durability and longevity. Construction - Our products feature thick lifting rings and one-piece cast construction for added strength and longevity., Manufacturer: ZOCWJK