Our 26-200 series spiral window balance is for non-tilt windows of any brand which is used to counter-balance the window sash. Not as popular as it's cousin which is our 26-100 series spiral balance, it is used by window manufacturers and the blue tip indicates it supports a sash weight of up to 35 pounds and has a tube diameter of 3/8". When replacing tube balances you should always replace both sides as it will cause the window to become unstable replacing just one side. When selecting the proper length of balance measure the metal tube only. Enter the tube measurement above. ie 26", 14" etc.