The Raspberry Pi 3A+ has a smaller form factor than the 3B+. These two Model 3+ Raspberry Pis are the last ever of the "classic" Raspberry Pi range.

The Raspberry Pi Foundation chose Pi Day 2018 to release the new Pi 3B+. It's not a big change from the Raspberry Pi 3 and it is selling for the same price of $35, but it does represent a significant improvement in performance. 

This is a nice idea - cases for the Raspberry Pi that look like old personal computers. If you are of a certain age this is a blast from the past.