Standard 3/16" bearing/cam with Constant Force Balance System for double hung vinyl windows.

Each 1/2 inch wide coil spring has a number imprinted on the plastic housing that determines the strength of the balance. 

They may have one or more coils and the coils may have different numbers on each coil if used in doubles or triples or quads.

Number Marked on Single Housing:      3 - 10    (Select weight by 1 number).

Number Marked on Tandem Housing: 11 - 20    (Select weight by 2 numbers)

Number Marked on Triple Housing:     21 - 30    (Select weight by 3 numbers)

Number Marked on Quad  Housing:     31 - 40    (Select weight by 4 numbers)

Housing Dimensions for single:

Width: 1-3/16 inches ( fits 1-1/4" pocket)

Height: 2-1/8 Inches  ( varies by coils )

Thickness: 9/16 inch

Priced and sold each.

NOTE: The RT562 has three different mounting clips. We will send which ever one we have in stock at the time of the order. The newest style has 2 screw holes.