Changers are designed to pull on center as indicated by the white line. This eliminates the changer levers twisting when pedal or knee levers are pushed. The control levers are spaced to allow the pull rods to pass between them eliminating a place where dust and dirt can build up, which can cause the changer not to operate correctly. The levers do not touch each other. The rollers are anodized to prevent strings from wearing grooves. They are machined with a string slot and a shoulder to catch the string end if the string breaks.