This is Pentair PCB 521320 Rev B IntelliChem Controller PCBA Board PCBA 521319 used part.

This part was removed by HVAC installer from a fully functioning system. Old system was replaced with newer one (more energy efficient) and was in good working condition. This part was inspected by professional HVAC installer. 

This part is in excellent cosmetic condition, very clean.  Please see more details from the images attached.

Please check images carefully because you will receive exactly the same as pictured, or a very similar one. 

FREE USPS First Class mail delivery guaranteed.

My handling time is 1 business day only. 

There is no warranty, it comes for parts only.  No returns will be accepted.