MEOPTEX1.25" Astrophotography Flip Mirror with Precise Micro focuser & Eyepiece Adapter

I love the flip mirror aspect, but have been unable to use the focus ring to achieve parfocal length between my eyepieces and a ccd cam on the back. It just won't go short enough for the Webcam. I knock stars off this review because there was literally NO documentation supplied in the box. I'm going to keep hunting for a solution but wish I had just bough a cheaper option that didn't even have the focus ring since it is useless for me.