High efficiency: The scissor-type design increases clamping force as the pulling force increases and allows for a larger jaw opening, so this pallet puller clamp can complete the stone clamping process in a short time. Stable and reliable. Its robust chuck and chain structure work together to enable the product to lift stones up to 325 kg/716.5 lbs and withstand high-intensity stone clamping work. The adjustable opening is adjustable from 12-36 cm / 4.7-14.2 inches, so it can also accommodate stones of different sizes to meet your diverse needs. These robust and durable curb clamps are forged from high-quality alloy steel and manganese steel, offering advantages such as corrosion resistance, rust prevention, long service life, high gloss, and excellent performance. Easy to use: The rock grabber comes pre-installed, requiring no additional installation upon receipt, saving time. The included chain allows the product to be suspended from excavators or other machinery.