Siemens 3TK28 34-2AB20 Safety Relay Press Control Unit, Two Hand Control Unit, Spring Loaded Terminals, 2 NO Enabling Contacts, 24VAC Rated Voltage, 45mm Width: Electronic Relays: Amazon.com: Industrial & Scientific
Siemens 3TK28 24-1BB40 Safety Relay, For Emergency Stop and Protective Doors, Autostart, Screw Terminals, 22.5mm Width, 2 NO Enabling Contacts 22.5mm Width, 2 NO Enabling Contacts, 24VDC Rated Voltage: Electronic Relays: Amazon.com: