"PB Swiss. You can buy them in the US from Tool Lady. They are expensive, but worth it if you use them all day every day. I've had a set of bits for 15 years, the slotted (common) bits show no signs of wear. They also make great posidriv bits. Disclaimer: I do not work for said company, I was just giving an example.
I picked up a tool kit from Radio Shack, about $16.00 to do my HD switch. I had checked Home Deport, Lowe's and a couple of local stores. I needed the #6 Torq and no one had it. This set is complete.
