The Avid Revolve Bobbin Swinger Arm is a classic-styled swinger arm, purpose-built to complement Avid Revolve Bobbin Kits. It lets you customise your bobbin weight with the 20g sliding weight, attached to the 11cm arm, and is finished in a sleek black anodised finish. - Classic-styled swinger arm, purpose-built to complement Avid Revolve Bobbin Kits - Customise your bobbin weight with the 20g sliding weight, attached to the 11cm arm - Finished in a sleek black anodised finish