C.R. LAURENCE FH2120 CRL 21" Tubular Spiral Tilt Window Balance Red Bushing. These CRL Tubular Spiral Window Balances for tilt type windows will replace a 9/16 inch (14.3 millimeter) metal or plastic tube balance with a sash load capacity of up to 25 pounds (11.3 kilograms). It will also replace the same size spiral balance with a white bushing. The 9/16 inch (14.3 millimeter) size of the metal tube is commonly referred to as 5/8 inch (15.9 millimeter) in the industry. While this balance is packaged and sold individually, it is our recommendation that both balances in the window be replaced at the same time.. Part Numbers Variations: FH2120