In addition to the markings on the channel as shown in the photo, the metal part of the channel is 1/2" x 27"; the sliding window itself is approx. 29" x 34" and has 'ATRIUM' stamped onto the locking levers. The cord broke...thank you!
Paul from SWISCO responded:
August 26, 2016
Thanks for posting. Please see our Series 395 channel balance, this looks like it's fairly close to your pictures.