The 12.5mm Orion Illuminated Plossl Telescope Eyepiece is great for accurately aligning your computerized telescope because the LED illuminated double crossline will tell you when the star is dead center. Also use it for guiding during an exposure.
When first purchased this item worked well. After that use it was stored in a customized foam cutout in a hard case. When I attempted to use it a second time, the illuminator didn't work. Thinking I inadvertently turned the illumunator on when I stored it, I replaced the batteries. To my surprise, the illuminator flashed on several times while closing the battery compartment -- even though the switch was off -- and it failed to turn on when the battery compartment was fully closed. It does work *sometimes* when I loosen the battery compartment slightly. Very frustrating!