Air coreholders can accommodate cores with a broader range of inside diameter tolerance. They expand concentrically for smoother operation, grip firmer, and release easier. An air coreholder is required in the rewind position if the machine is going to be used for slitting. Flange mounted air coreholders (picture below) are bolted to the machine spindles with fasteners which require time and tools to remove and install. Rolls must be installed and removed by lifting them over the coreholders. They grip and release by simply flipping a toggle switch. Compressed air is piped to the coreholder through a sealed passageway in the spindles (hence the need for permanent mounting). Flange mounted air coreholders are compatible with the optional foot treadle valve for hands free operation.