spiral balance 30 inch long and has a " T" on the end

Hello, thank you for posting,

Based on the T- end, you will need non-tilt spiral balances. Please review the Series 400 with a 3/8" diameter or the Series 500 with a 5/8" diameter to confirm the best fit. Match up the colored tip for the correct spring strength to support the sash.

If the colors do not match, you will need to weigh the sash and compare to the strength chart on the corresponding series and length's product page.

Please review and let us know if you have any additional questions!