15/16" x 4-1/4" radius face, 5-7/32" hole spacing, 1/8" offset, 5/8" throw, 12" rod length, with a square nylon tip with beveled corners fits in a 1/2" square hole.
The International FG-1200 Flushbolt Guide is the piece that fits into the top or bottom of the door and acts as a guide for the Flushbolt Rod. The piece measures 1-3/8" x 1-1/2". The square hole in the piece is a 1/2" square. The manufacture part number is FG-1200.