Andersen Window - Operator Channel / Track with Square ButtonAndersen Window Operator Channel Track with Square Button Andersen 14 1 2 inch Channel is made for 7073A & 7073B Operators with square plastic swivel buttons on the end of the Operator Arm. They were used by Anderson from 1960 1974 . Channel will work with both Left and Right Hand Operators. This track will work for both left and right hand Operators Also works on Operators with round or square buttons. The New Track style has a grove on both sides