Flexible knife and curved scabbard for horizontal carry. Blade and handle both flex.

Back of scabbard marked:

FLEX ( KNIFE
by Artus
Pat. Gesch. [Patent Registered (applied)]

Artus GmbH [Inc.]
Postfach [Post Office Box] 20 00 12
30896 Wedemark [a residential suburb of Hanover, Germany]

The knife profile seems to be based on the Al Mar Knives SERE, but Al Mar Knives confirms there was NO connection between AMK and Artus.

Artus of Wedemark began advertising the Flex Knife in March 1994.
Ads continued through 1997. Mr Henning Ritter reports,

All magazine reports Concerning the FlexKnife are within this 1994 to 1997 time frame.
ARTUS company attended just one time the only German show (IWA Nuremburg) for the branch in 1995.

Artus of Wedemark was probably not connected to the present Artus bioscience of Hamburg. [Artus = Arthur.]

The owner writes:
The knife handle is sectioned internally to flex and the blade is some sort of flexible steel.
It mates perfectly to a "curved sheath" that conforms to the curve of your waist (well not my waist, but you get the idea).
I seem to remember a custom maker who was making curved blades and sheaths, but the actual blade was curved and not bendable.
This whole unit "flexes".
Overall length 9-1/2 inches. Blade length 5-1/4 inches.