To be fair, the drone size descriptions in Arsenal (at least for mini and micro drones) are a bit skitso anyway.
QUOTE
Microdrones (Body 0): These insect-sized drones are typically
under 10 centimeters in length. They receive a Concealability
modifier of –6 (see pp. 301–302, SR4).
Well, if they are insect sized, I certainly hope that they are less than 10cm in length, cause that's just under 4 inches, and that's a
big bug. Which raises the question of what do they mean by insect size? Is the average Microdrone the size of a House fly? Cause thats what I think of when I think "insect sized", and thats 8-12mm long. Or is the average Microdrone the size of a Cicada, which measure 2-5cm?
We know they have a concealability modifier of -6, which theoretically puts them around the size of an RFID tag, which is described as "Ranging in size from
microscopic to the size of a price tag". Slap patches are also in this category, but the book doesn't actually say how big they are. (I would imagine about 2 inches square)
Then Minidrones:
QUOTE
Minidrones (Body 1): The size of a large insect or mouse,
minidrones range from 10 to 25 centimeters in length and fit in
the palm of one’s hand (or a pocket). They receive a Concealability
modifier of –2 (see pp. 301–302, SR4).
So these are the size of a "large insect or mouse". Well, the house mouse is about 10cm long (in the body) at its biggest, though the "Fancy Mouse" can range from 15-30cm, but that includes the tail and tiny top hat, so the actual body is about half that. Alternatively, they are described as fitting in the palm of ones hand, which fits with the whole "mouse" description. But the actual length is described as 10 to 25 cm, or 4 to
10 inches. 10 inches does not fit into the palm of ones hand. (insert penis joke here). For reference, a normal (size 7) basketball has a diameter of about 9.5 inches. While you can hold a basketball in your hand, I wouldn't really say that it "fits" in there, and you
definitely cant put one in your pocket.
So lets look at the concealability. Minidrones are Concealability -2, which puts them in the same category as Light Pistols. The Beretta 92 (what I would consider a decent modern example of the class) ranges from 7.8 inches (for the compact version) to 8.5 inches. That fits pretty well in the 10-25 cm range.
Of course, the other issue is that both mini and micro drones can theoretically be 10cm "long" (whatever that actually means, what if its round?) Which would result in two objects of essentially the same size having a 4 die difference in their concealability. But whatever, those rules aren't perfect

Overall, it seems to me that in the case of mini and micro drones, the rules have
no idea how large they actually are. And that's kind of irritating.