IEC 60947-1, EN 60947-1 IEC 60947-5-1, EN 60947-5-1. 22 mm Push Button Heads, Metal (Shiny). Siemens extremely rugged IP69K push button heads, high-grade plastic actuating element with gloss metal front ring. Available in a variety of colours, illuminated, non-illuminated or mushroom style. Self-holding function of the actuator when mounting Twist prevention integrated into patented holder design Suitable for use in extreme environments No special tools required Simple geometry for mounting holes