What Raspberry Pi products are subject to US tariffs?

Question

I actually thought that all RPi products would be classified electronics and subject to the 10% tariff on UK electronic goods. I believe the way tariffs work is the importer would pay the tariff when the item was received in US Customs after the tariff was in effect. 
 I was surprised by which items had tariffs applied on a recent order from Mouser (a US distributor). I've been waiting for the RPi5 16GB to get back in stock and ordered one on March 20 before that shipment sold out. I expected to pay a 10% tariff of $14.80 on my order but was charged $1.60. I had ordered a 27W power adapter, 2 active coolers, and 2 Pi Bumpers in addition to the RPi5. I was surprised that tariff costs were only applied to the active coolers and bumpers. 
 I also have recently received some electronics directly from China that had no tariffs charged, I guess I shouldn't complain but it is hard to not know what to expect.

cstanton · Answer

Hey ralphjy 
 I'm based in England, and I don't have an authoritative answer for you per say, but I searched online and I found a bit of a rabbit hole where I encountered this: 
 https://hts.usitc.gov/ 
 According to a previous ruling, as an example: https://rulings.cbp.gov/ruling/N285104 
 " The applicable subheading for the Raspberry Pi 2 Model B (P/N 70465426) will be 8471.50.0150 , HTSUS, which provides for &ldquo;Automatic data processing machines and units thereof&hellip; Processing units other than those of subheading 8471.41 or 8471.49, whether or not containing in the same housing one or two of the following types of unit: storage units, input units, output units: Other.&rdquo; The rate of duty will be free." 
 This was in 2017, and provides the following link: https://hts.usitc.gov/?query=847150 which are kept up to date. 
 
 After clicking the magnifying glass we get that there's two main rates of duty, and one can be free, and one can be 35%.