A few years ago I purchased the Big Orange in line head vent odor eliminator. It's a activated charcoal element in a hard case. The element requires replenishment every few years. This unit works perfectly. Last week I decided to replenish the element and ordered it on line. This is the response I received:
Big Orange
I noticed that you recently ordered a "1.5 OEM" refill kit but on a previous order you requested a "Orginal" style refill. Please confimr which one you would like.
If you have any questions, reply to this email or contact us at info@bigorangefilter.com

Of course they were right I had ordered the wrong replacement. A full refund was issued and I placed a new order for the right element.
Terrific customer service!