9 mm internal hexagon is required

The description on the verified manufacturer/distributor website states that the crimping area is hard-soldered ("Pressbereich hartverlötet") and that the product comes with a flared insulation sleeve (aufgeweiteter Isolierhülse)

Manufacturer's item number: 00858

er en direkte komponent til elektrisk tilslutning af ledere med angivet skruefastgørelse

The manufacturer's page explicitly mentions examples of applications for the 2035 series: electricians

Bit serie 4 lige kærv 1/4"; 0,8x4,0x70mm Unit(s):Packet 9 mm internal hexagon isProduct Overview 800 4 Z bits are screwdriver bits designed for slotted screws. The bit is part of WERA's 800 4 Z family and is described by the manufacturer as "tough for hard materials". The product comes with a 1 4" hexagon drive (Wera connecting series 4) and is compatible with holders according to DIN ISO 1173 F 6. 3. Features and Function 800 4 Z bits provide a standardized connection surface via the 1 4" hexagon drive, allowing mechanical