This product is now obsolete. Its closest replacement is https://gblockingsystems.co.uk/locking-systems/c4a-4-call-for-assistance-kit/
Kit & Accessories:
Disabled Toilet Alarm Kit
Main Control Unit:
• Integral power supply with monitored on-board rechargeable battery.
• Integral NO/NC Relay.
• Integral Reset button with Braille.
• Power on indicator for mains supply