Left or right hand side, uni-directional (moves only front to back). The really long ones' for the old Mac Digit have been discontinued. This is the only one that is currently available at 9 inches. It DOES NOT include the tip, and will only accept the old barrel type, part S_367 tip.
WARNING: This product can expose you to chemicals including lead, which are known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, go to www.p65warnings.ca.gov.