channel balancer

A professional from sarasota fl says:
I work as a window washer my cost needed new ch balancers 19 inches stamped number on it 28D USB i can not really identify what series i need ,it is 5/8 wide. Thanks!
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Tom from SWISCO responded:
The 28D is Swisco's 2840, and measures 29" in length. You will want to try and match the top and bottom fittings of the current balance to the replacement options we carry online.
A professional from sarasota fl says:
Yes i have typed wrong on 19 inches. These are the top and bottom i have try to match but i am not sure ,if u could help me the numbers on it 28d.Thanks!
User submitted photo of their 28TD channel balance.
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Casey from SWISCO responded:
Looks like SWISCO balance series 380. The 29" length balance with 28D normally translates to 2840, to check, remove the window sash and place it on a scale. S380-29 with stamp number 2840 will carry a window sash weight range of 23 through 28 pounds.
Suggested sash weights do not include the manufacturer's sash friction due to manufacturing methods and weatherstrip types.
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