Video - Apollo 1500/1550/1551 (816) Linear Actuator Swing Gate Operator February 28, 2020 22:59 Updated Related articles 816 actuator limit assembly tower replacement instructions Apollo 816 Linear Actuator Installation Reference Manual How do I get my 816 extension tube back to factory position? Apollo 816 Linear Actuator Part Diagrams Invalid Radio Channels/Remotes on a 1050 Control Board.