The filters they sell are actually brandless products from China... That makes APS a Trademark, same as SUNSUN from China which sells the exact same products. In my region, there is also a shop selling these same filters with his own fantasy brand/tradename.
I've bought several SUNSUN filter products via Ebay and Aliexpress and wasn't disappointed.. Price and Quality is reasonably ok and after 4 years of use yet no quality issues.
It's a choice to make and a risk to take, from China they come to a tad cheaper under different brand names, but it leaves you with a hassle if you ever need service or warranty. Then the extra money spends in a UK shop is worth it, having a face to talk to if needed.