Identify Channel Balance

I need to replace a channel balance in a window purchased in 1989. The length is 17 inches, depth is 3/4 inches and it is 1/2 inch across the opening. I have attached photos. The markings say " 16 D Fiberlux Mt Vernon , N.Y." Thank you.

Iin regard to the channel balance that I need, I forgot to mention that the window is not a tilt in. It is the botttom of a double hung window. Thanks.