The GRPA is a high performance, heavy duty steel core chuck with air-activated pistons that mechanically drive ramped expanders outward for perfect centering. The chuck is available with either expanding leaves or lugs and with either flange or shaft extension mounting. Also available are lightweight Adapters that easily slip over and lock into the base chuck with three locating pins for quick changeover to larger size cores and transmission of torque. The GRPA is recommended for higher weights, speed and torque requirements for either stop and go or continuous operations and for any unwinding or rewinding where perfect centering is required.