5/8 Inch Tilt-In Spiral Window Balance Rod w/ Blue Bearing
Bearing color denotes rod strength.  Red and Blue Bearings are up to 30 pounds, Black Bearings are 30-40 pounds

Type: Tilt In window 
Tube Diameter: 9/16 inch 
Bearing Color: BLUE 

NOTE: We substitute Red Bearing, if we are out of Blue
Has double end pins: one locks into the balance shoe and one for adjustment. 
Specify rod length in order 
(measure rod length from end to end of metal tube).

Resources:
Guide: HOW TO ADJUST A SPIRAL BALANCE ROD
Video: HOW TO REPLACE A SPIRAL BALANCE