You searched for "pluggable function"
Phoenix Contact
Phoenix Contact Single-Channel Emergency Stop Safety Relay, 24V dc, 2 Safety Contacts
Part: 2702095
Single-channel 24V DC emergency stop relay with manual reset function.
Pilz
Pilz Dual-Channel Expansion Module Safety Relay, 24V dc, 2 Safety Contacts
Part: 751101
Safety expansion module extending relay functionality for multi-channel machinery control.