Series 280 - T-4 (4mm diameter) Handle for Reversible Blades
Fits 4mm diameter blades only (Felo Series 280 and Wiha System 4)
It seems that Wiha no longer makes a collet adjustable 4mm handle. This Felo fits my 4mm blades perfectly, is very comfortable, and seems to be very high quality. My only complaint is a small bit of flashing on the rubber finger grip.
I bought this handle to supplement the handle in a Wiha 62995 set. It is more comfortable in my hands than the Wiha handle, and the collet seems to work well to allow variable blade length. Even given the price, the fit and finish was not quite what I expected from Felo. The rubberized grip had some noticeable burrs, for example. Still, overall I like it and expect to get lots of use out of it.