The tool's primary features and materials are documented in the manufacturer's official datasheet for the 1567 series

Source: Product information on Intercable Tools product page (ICF12012)

handle diameter 18 mm

The information above is based on Intercable Tools' product catalog for the R-series with inspection hole (product information provided in input)

View data sheet from the manufacturer

Bøsning BI-SLB4-F/A 4 mm, blå MIL2006101304 The tool's primary features and. Insulated, rigid, 4 mm, accepts spring loaded 4 mm plugs with rigid insulation sleeve. Machined brass. Socket is screwed into pre drilled plastic, metal, etc. panels. Connection: Flat connector tab 4. 8 mm 0. 8 mm, can only be bent to 90