Spiral balance for tilt windows white color cap

Thanks for posting. If the outer tube, up to but not including the colored tip, is 27", and if its diameter is 5/8", then you need an S600-27 Spiral Balance. You will need to select a color tip option, which designates the strength of the spiral balance. This is denoted by the color of the tip from which the inner spiral protrudes. If there is no color or you are uncertain, weigh the window sash that this spiral balance supports. You can then match that exact weight with one of the weight ranges listed alongside each color tip option under the S600-27 product description. Let me know if you have further questions.