Do you sell the 18 4 DK Channel Balance?
Hello! Thanks for reaching out.
I'm not sure what balance you have, unfortunately. We have dozens of different products with that stamp. Please note that it's not a product code or anything, it just indicates the strength of the spring.
In order to figure out what Series this is, I need you to remove an undamaged version of this balance from the window and show me clear pictures of the top and bottom nylon fittings. I will also need to know the dimensions of these fittings.
Great! In that case, with a stamp of 18-4 my top recommendation would be the 1840.
Please let me know if you had any other questions and I'd be happy toa ssist.