... 2.Feature :with anti-impact design 3.According with standard ISO4190,EN81,GB /T24477; Description : Metal square push button with vandal-proof ... design 1. The push button adopts zinc alloy body with anti-impact design , the surface processing can be customized by ... different electroplated; 2. According with standard ISO4190, EN81,GB /T24477; 3. The contact type ...