Window Channel Balance

I have a removed 28 inch window channel balance. It has a stamp on it 27B. It does NOT have shoes on either end. The bottom window tilts in to remove this channel balance. This is a single hung window. The depth of the removed channel balance is 1/2 inch.I bought a replacement channel balance but it is 5/8 inches in depth. I installed it and there seemed to be excessive friction.Do you make channel balances that are 1/2 inch in depth???

Paul,
Here are some pictures of the removed channel balance. Like I said the removed balance is 1/2 inch deep. The new purchased balance is 5/8 inch deep. The extra 1/8 inch seemed to create alot of friction against the up and down movement of the window. For what it is worth I removed a sticker from the window. It reads, "Florida Extruders International, Inc--Single Hung Window---W/N 04793.
The stamp on the outside of the channel is 27B.

The balance does NOT have plastic ends. It just is attached with one screw into the channel.