The XMark preacher attachment model # XM-4426 is ideal if you have a bench with expansion potential. This preacher attachment easily slides into most XMark benches where the leg developer would be. This interchangeability allows you to alternate between bicep and leg exercises on the same bench so you don't have to sacrifice space. For good form during your exercise, the Xmark preacher attachment is properly angled to support your arms comfortably and effectively while curl work is performed. For use with benches that have a 2" x 2" receiver. The Xmark preacher curl attachment has 3 position heights.