Changes

The height of the case has been reduced from 43.8mm to 37.8mm, as the [https://wiki.geekworm.com/File:IMG-5694.jpg snap-on radiator] has been replaced with [https://wiki.geekworm.com/File:IMG-6118-size-1.jpg aluminium heatsink] with a maximum height of 10mm.

N508-V1 does not reserve the antennas holes; N508-V2 reserves 2 antenna holes, also solved the problem of inaccurate hole position of N508-V1.