Hasselblad 42250 focus screen question

I've read conflicting descriptions of the Hasselblad 42250 Dot/Grid focus screen. Is the center "dot" a micro prism or just clear ? I have a 500c with the original concentric screen with the cross hair design. So far it has been difficult for me to focus, and I am considering another screen. (I do realize the 500c requires removing screws etc to change screens and plan to have this done by a professional repair shop)

Thanks for any help!
GP

Think this says microprism don't have mine to hand.

http://www.forums.camera-info.com/threads/focusing-screen-dilema.9388/

The 42250 is a center microprism circle with etched grid lines outside the microprism. It is the screen I use most.

Here is the description in one of my Hasselblad product flyers;

42250 Interchangeable checked focusing screen with central grid 2
A 15mm microprism central grid is combined with a checked pattern in this focusing screen. The checking is used for horizontal and vertical alignment in e.g. architectural photography and copying work.
For Hasselblad 500C/M, 500EL/m and 2000FC.

Click to expand...

This is the screen I use most of the time. In a lot of situations, the microprism is a little more convenient than the split image, which is the other choice for non-acute matte screens that have an alignment grid.