Need replacement sash balances

Thanks for writing in. If the metal channel, not including the nylon fittings, is 37" long, then see either our S380-37 or S385-37. The only difference between these two balances is the 'depth' of the bottom nylon shoe, so compare both with your old balance to see what matches best. You'll need to choose a stamp option. If there are no stamp codes on the balance, you'll need to weigh the window sash. You can then match that exact weight with one of the weight ranges listed alongside each stamp option on the product page.

For your other balance stamped 30 3, you'll want to confirm if the nylon fittings are the same as they are on your 37" balances; if so, then this may also be a Series 380 or Series 385. If the balances have different fittings though, we'll need to see pictures of them with the balance out of the window. You also should confirm the length of the metal channel, not including the nylon fittings--it actually should be 31" long, no 30". Finally, you'll need a stamp option of 3030. Let us know if you have any other questions.