Single hung vinyl replacement window balance

Question

Manufacturer of window is unknown. Balance is marked with:
13 4 ET CMC 2

Thanks!

Brian

User submitted photos of a window balance.

Tom · Accepted Answer

If this metal channel is 14" long, then this is SWISCO's S351-14 or S390-14 channel balance. Measure as shown below to tell the difference. The Series 351 uses a smaller 1" shoe than the 1-1/8" shoe that the Series 390 uses. The "option" for this balance may be 1340, but you'd need to weigh your window sash to be certain. 1340 holds 11 to 12 pounds of sash.

Comparison of 15-001 & 15-002