4 Powerport 2
The successor which was larger and meant to reduce sparks (which I never saw anyway)
The 3rd is the successor to the 2nd which was smaller than the original 1st one and much smaller than the 2nd one
WE then have a now a totally different product which is the Powerport II 2 which is for USB-PD and QC devices
If you have a modern high-end set of devices like Chromebook, larger tablet, a Quickcharge compatible phone, then consider the 4th link. Otherwise go for the 3rd link is it the smallest and the first 3 links are electrically identical all recharge the same performance so go for the smallest. If you do want to save a few $ and do not care for size then go whichever is cheaper of the 1st, 2nd, 3rd link.