Both the Antec A40 Pro and the C400 coolers from Antec ship in similar-looking boxes, and each have large product images on the front.
Inside, both come with essentially identical manuals, while you also get the necessary mounting hardware plus a small tube of thermal paste.
On the left we see the A40 Pro with its smaller 92mm fan. Its total dimensions are 100 x 75 x 136 mm, and this puts it in the same size category as the be quiet! Pure Rock Slim and the Cooler Master MasterAir Pro 3. This means it is a very compact air cooler, positioned in between a low-profile cooler and a more standard cooler like the Hyper 212 EVO.
That leaves the C400 on the right, and this comes with a pre-installed 120mm fan which, incidentally, sports integrated blue LEDs. It is also a fair big bigger than its cheaper counterpart, measuring 155 x 125 x 76 mm, and this makes it a direct rival to likes of the Cryorig H7 and the Hyper 212 EVO.
Both coolers feature 4 copper heatpipes, though, as well as smart-looking top-plates which definitely helps with the aesthetic side of things.