I need a spring for this balance. If it possible just replace spring. If not full ballance

Thanks for posting! Your balance shoe appears to be the 15-180 Coil Balance Shoe which is compatible with the Series 190 Coil Balance. To determine which spring is needed for your assembly, you'll need to look for any stamps/markings on the coil.

If there are no stamps/markings, you'll need to obtain the exact sash weight and divide that number by (2). For example, if your sash weighs 12lbs, you would need the S190-640 6lb Coil Balance.