On Tuesday, April 18, 2017 1:39 PM, Gregory Hahn  wrote:
 

 If you are just focusing on Xcelite, it's called the "99 series" type. In my
collection, I have phillips, slotted, hex, nut-driver, reamer, and extension
bits, plus a racheting handle and a non-racheting tee handle. Casting a wider
net, I have handles by different makers using the same idea, but not the same
size wings, both as single shaft bits, and the type with a phillips on one end
and a slotted on the other with the wings half way between. The oldest of the
last type I have is the screwdriver from the toolkit of my first car, a '68 VW
Bug. I suggest "interchangable" or "reversible", depending on where the wings
are located.-Greg