Pivot bar and pivot lock
Width is 45/64 inches by2 27/32 length
35/64 depth
Pivot bars are 3 inchs in lenth
Thanks for posting! Your coil balance assembly reminds me of our Series 140 Quick-Tilt Balance. Although, I would suggest double checking that yours has a 1-1/4" width and a 9/16" thickness.
Since your assembly does not appear to have a stamp, you'll need to obtain the exact weight of the sash and divide that number by two (the total number of coils in the window). This should give you the stamp you'll need to choose from the list of Series 140 balances.
There are two different pivot bars compatible with the coil balance assembly; they are the 26-398 and 26-405. You'll need to be sure to confirm the placement of the installation holes to determine the best fit.