Nordic Pure, I buy a box of 6 from the company's website , delivered to the house. They are changed every 2 months, used for heat and AC. The following link which evaluated filters was used on filter to make my decision.
I started with a MERV 12, then went with a MERV 8 and recently bought a MERV 10.
https://www.nytimes.com/wirecutter/r...-we-would-buy/