Knob body: Technopolymer plastic (Polyamide PA), black matte finish
Cover plate: Aluminum, anodized, natural finish
Socket set screw: DIN 916, steel, black oxide finish, with internal hexagon and serrated point
EN 954.3 hand knobs fit EN 954 position indicators. The set screw in the hand knob links the knob to the hollow spindle of the indicator and the adjustable spindle.etc.