C.R. LAURENCE FA2440 CRL 25" Window Channel Balance - 2440 or 24-4. This CRL Window Channel Balance replaces single or double hung window balances with a stamped number ending with "40" or "D". While this balance is packaged and sold individually, it is our recommendation that both balances in the window be replaced at the same time. This will restore the sash to a near new condition, and prolong the life of the window. Whenever replacing Window Channel Balances be sure to check the guides, take-out clips, sash cams and terminal clips, as age and weathering can make plastic and nylon parts brittle and worn. Even metal parts will show fatigue with constant use, so be sure to inspect them too.. Part Numbers Variations: FA2440