U buy something that they 3 d print for you and after u have to put it together . If u have access to 3d printing is a lot of free files to download to get something similar
looking at those prices, it would be better to just bloody buy the device, I mean really, lol, sure it is convenient if you have a 3d printer, but why would you buy, this, have it shipped, still have to get the dna30 chip, and assemble, and include your own batts... eish, I don't know, that is perhaps for people whom already have the device but broke it, like replacement parts or something, LOL