perfect support from FLO, I originally ordered the wrong flattener, but in the end Chris advised me what would suit my camera, it was not a problem to cancel the order and create a new one. I highly recommend this store

The WO Adjustable Flat6A III 0.8x Reducer / Flattener is solidly built and has a graduated scale for accurate back focus adjustment. I use this on my GT71 with a WO Camera Rotator, this enables me to rotate the Camera Rotator, rather than the camera to adjust back focus. Just need to sort out some optical train tilt now but I wholeheartedly recommend this product.

Just got my GT71 with this flattener.
I made couple of shots this the telescope - amazing picture quality even compared with my 200mm reflector (and is not so demanding to the mount and guiding of course).
Didn't fit the flattener yet - I am confused with the numbers above - if one subtracts recommened adjustable distance from the backfocus distance from the table, one gets 53mm, not 55mm.
WO website has the different by this exact 2mm numbers. Probably this should be fixed?
I'm eager to test the whole setup next night anyway.

Only minus - really hard to mount / dismount 2" filter inside

High quality gear and easily adjustable to get the correct spacing according to the OTA it is used on.

Pure quality as always from WO and great service from FLO, also it came in space grey as my scope is how lucky was I.

I have finally had the opportunity to try this out in combination with an older - Zenithstar -Williams 110 mm F 7.0 refractor. Connection required the M63 adapter nosepiece. The reducer/ flattener does an excellent job. Nice round stars right to the edge of a field that has increased just as expected for 0.8X reduction. FLO did an excellent job of sorting out the adapter problem (which I hadn't originally appreciated) and chasing it up for me as soon as it came available.