That's great, system 6? I'll give it a look. I really need a set of compact, thin shafted security bits, any recommendations?
I do have the interchangeable head version, but so far I've not had trouble but its just a matter of time.
The System 4 shafts are thinner (4mm as
robrenz stated), but don't have all that many styles available in the US currently.
The US version of the System 4 Drive-Loc is a very good basic set (Philips, Flat, Torx), that will fit most recesses I've encountered however. Europe also offers at least Hex, Ball Hex, Bit Holder (takes their standard system 4 bits), and Pozidrive blades for the System 4 IIRC. Perhaps a couple of others. Go to Wiha's European site, and download the catalog and see for yourself if you wish. That's how I found that additional blade styles exist (blade styles available has been my one complaint). Given your location, it may be easier to locate the additional styles and sets that aren't yet available in the US market.
BTW, the handles are more comfortable and allow you to get more torque on the screw than the more common micro sized screwdrivers IMHO (either system). Requires less storage space too, if that's a concern.
The system 6 (might try searching with "Drive-Loc System VI" if you have a hard time finding it), does carry security bits, and a lot of other styles (nut drivers in particular). But you may run into an issue where the recess diameter is smaller than the shaft with this series on occasion. This is my one complaint, and why I keep hoping for more styles to be offered in the US. There will be limits of course as to sizes possible with a 4 mm shaft, but the smaller screw sizes makes better sense in a 4mm shaft IMHO as there's a much better chance it can fit in a recessed location (run into too many instances where I couldn't reach a screw with a .25"/6.3mm shaft).
I found it easier to browse the catalogs and then punch the part number you are interested in into the CTB search box for pricing and availability. They have so much stuff on the site it is frustrating even when you use the categories on the left sidebar. But their prices cannot be beat.
I use the catalog method as well.
BTW, I thought Chad's was getting out of Wiha due to competition from Amazon.
The reason I'm thinking this, is that they don't link Wiha's catalog, and they don't have listings for all of the products (seems they have listings for what's in stock on a cursory glance). For example, if you look up the System 4 Drive-Loc set (26985), nothing. Couldn't find any of it under other terms either.
Aside from Chad's and Amazon, there's KC Tool Co (
http://www.kctoolco.com/) for good prices and shipping seems reasonable. Not sure this will help saturation, but might be useful for US/Can members.