New Vinyl double hung window balance kit

Good Morning, Can not find any information on the windows but was installed in house in 1999 and I have replaced a few about 10 years ago. The only information that I can find is inside the window "Malta 7B 1". I have taken pictures and the size is:
54 5/16" long end, 53 1/2" short end, W 3 1/2" two springs with two pulleys on top. White Vinyl
Paul