These filters are 5.75 x 5.75 inches and 12 mm thick. They were purposely designed to be
sandwiched between the brightest and most variable night sky lines.

They are being used by us to image deep fields. The team currently consists of Rogier Windhorst,
Haojing Yan, Stephen Odewahn, Seth Cohen (Arizona State University) and Bill Keel (University
of Alabama).

If I get the chance I may add a link to the profiles and other relevant information.