Window balance

Hey Chris. Your photos show the top nylon attachment or fitting, which has wings or 'side tabs'. Does the bottom attachment, or what we call the shoe, have these wings as well, or does it lack them? Judging from your first photo I believe it lacks these wings, but since it's not totally in the frame, please confirm if it does indeed have wings, or just send a clearer photo of that bottom fitting if you're not sure what I'm talking about. 

Assuming the bottom fittings lacks wings, you have an S395-37. For a stamp option choose 3650. Let me know if you have further questions.