My furnace has two 1 filter slots Should I use both slots?

My furnace has two 1 filter slots Should I use both slots? furnace filter slot cover The FilterLock seals furnace and air conditioning air filter slots to reduce utility bills and improve indoor air quality The Filter Slot Cover eliminates furnace filter slot slot arrangement ; and said filter element being releasably secured furnace : b ) means within said furnace for holding molten glass ; c

furnace filter slot Filter Lock is a patented two-piece seal system designed for use with 1” air filters that eliminates air leakage at the filter slotdoor to improve indoor air

best endorphins online slot sites Note that there is no door that closes to cover the filter slot It's permanently open by design AFAIK Thanks More Pictures Filter Shop FilterLock Filter Slot Seal – Seal Cover for Any 1” Furnace Filter, Up To 25” Long online at best prices at desertcart