HRV has two sizes of filter be sure to get the right one
HRV introduced a new plastic box HRV around 2014 which is 5mm smaller than the original steel (galv) box HRV
It is so important that you get the correct filter or it will be too small or too Big and will not filter.
If you have purchased a filter and been told one fits both you have been mislead and shound ask for money back or the correct sized filter at no extra cost.
Supercell Generation 1 (STEEL BOX HRV)
Supercell Generation 2 (PLASTIC BOX HRV)
If you are told to rip pices off your filter to make it fit don't buy it.