To correctly measure your balance, measure the metal tube only!.SPIREX 48" R Series 100 Caldwell Window Balance That will be your length, you will then need to match the color of the coupling. This balance is designed for residential and commercial window applications.
46" Caldwell Series 300 5/8" Channel Block&Tackle -Stamp 45-2 No other parts are included. Includes the balance and pre-installed top and bottom guides only. 5/8" Channel Depth. If you have questions, contact us before purchasing.