This came from a very old window the only markings are the number 1820. I need two it measures 19 inches in length. 5/8 depth and 1/2 wide. The spring is 9 inches
Casey from SWISCO responded:
November 14, 2018
Hello,
It looks like you'll need our S377-19 with an 1820 spring strength option. Take a look and let us know if you need anything else. Thank you!