![UTC™ ATS1821 Relay Expansion Module [ATS1821]](http://shop.sysaway.com/cdn/shop/products/ATS1821_grande.png?v=1660906245)
Reference:
ATS1821
Expandable board of 8 open collector outputs for ATS centrals and ATS1201E expander module and ATS1250 door controllers module. Security grade 3 certified.