Meade's #909 Accessory Port Module works exclusively with 8.0" Meade LX90 series telescopes, not the larger sizes, and expands the functions of the computer control panel. It provides the Autostar handbox control over optional electric focusers and corded illuminated reticle eyepieces for guided long exposure astrophotography, as well as providing a port for CCD autoguiders(for longer exposure astrophotography).
The #909 attaches to the rear cell of Meade's 8.0" LX90 Schmidt-Cassegrain telescope just below the visual back/star diagonal. You will attach an included bracket permanently to the scope(using supplied parts and tools) and the #909 snaps into the bracket.
While the #909 can easily be removed by pulling forward on a clip at the top of the bracket and sliding the device downward, the module's actually small enough to be permanently left in place.
Many will prefer the combination of the #909 Accessory Port Module and the #1206 Electric Focuser, as opposed to #1205 Electric Focuser by itself, because the combination of the #909 & #1206 allows focusing control to be done by the Autostar hand controller instead of having two seperate units for movement and focusing.