If you own an automated flat panel cover with motor, you need this. I can finally use my dew shield with my flat panel cover and motor with my Edge HD 9.25" and 11 and my Meade 10" to automate my shooting sessions.
If you own an Eagle, an Alto and a Giotto, these last 2 get in the way of the Eagle's eye when mounted on top of the OTA. I had to install this dovetail under the OTA with the Alto and Giotto under as well, so that the Eagle has an un-obstructed view of the sky.
The only drawback of the dovetail is that the smooth side of the dovetail bar should also have the long grooves for fastening to the OTA. Actually, the smooth side (where there are no holes) is what should go under the OTA and onto the mount saddle.