Ring-brand Outdoor Siren for Alarm-US Availability?

I found a manual for a Ring-branded alarm outdoor siren on the Ring US web site, but I cannot find the siren itself for sale in the US-the only external siren I can find is the Dome indoor siren. The outdoor siren appears to be available for order for UK and EU customers (and possibly other countries), but it is unclear if the siren is compatible with US z-wave systems. I also noticed that there is a tab in the "Set Up a Device" for the alarm for the siren (Alarm Devices/Set Up A Device/Security/Siren), so now all I need is the siren itself! If anyone here has any info on how to purchase one of these and/or if the EU/UK version is compatible with US alarms and could post it, I would be much obliged. FYI, here is a link to the siren web page: https://support.ring.com/hc/en-us/articles/360054374931-Ring-Alarm-Outdoor-Siren-