Kinco window sash
A handy person from Colorado says:
October 4, 2016
29 3 B.S.I. or
Tom from SWISCO responded:
October 6, 2016
Thanks for posting. Sounds like you have a 30" block & tackle balance with a stamp option of 2930. I'm afraid that's all I can tell based on your information, though. Now you just need to pick out the top and bottom fittings in order to determine the Series.
I recommend that you look at our Channel Balance Home Page and follow the steps in order to find the Series that best matches what you have.