Andersen® 400 Series Tilt-Wash double-hung windows block and tackle channel balance.
The original balance had a metal clip that attached to the plastic brake shoe 
The current style, 2016-present, has the string attached to the brake shoe
When old style are not available, replace in pairs of the new style

Channel Balance Width: 9/16 inch
Channel Balance Depth: 1/2 inch
Channel Balance Length Varies by window height
Channel Balance Weight Varies by window weight
Brake Shoe, NOT included, Balance only

Most Andersen Tilt-Wash windows have an identification sticker in the top head jamb
1. Please Provide picture of sticker 
2. Customer Service needs the width & height of the visible / exposed glass (what you look through)
3. Picture of the glass code in bottom corner of glass ( glass type & weight info) 
4. If someone has removed the balancer, the bottom of metal channel has numbers stamped into the metal. The numbers will help ID which balance your window uses.
* To ensure you get the proper balance, Please provide, exposed glass size and picture of glass code 2.2 or 3.0

Additional Information:
• Used on windows manufactured from 1992 to present
• Balance was modified in 2016 - order quantity of two when ordering replacements for a unit manufactured prior to November 2016
• Balance allows for smooth operation and maintains the position of the window sash
• Balances are found in the side jambs of both the upper and lower sash ( 4 per window)
• When ordering balances Andersen recommends replacing all balances and the window side jamb liners 

Important Note: 
Order quantity of two when ordering replacements for a unit manufactured prior to November of 2016. 
The ‘easy release’ sash removal balance shoe requires updating both the right and left side sash balances.