It will work with 5U (MOTM and similar) modules, but it's really better for Dotcom/STG/Grove/Moon/SSL/MegaOhm and their ilk.
Details are here: http://www.muffwiggler.com/forum/viewtopic.php?t=48168&start=all
Price is $96.00 each, plus shipping (see several posts down for actual shipping costs). Most of my initial run are spoken for, but I do have a few left over and if interest is high enough I will do a second run for late February / early March shipment.