Difference between Wheelock RS and RSS?

TheLilRubix put up a new mini system test video where he shows that his strobe is in fact a Wheelock RS, rather than an RSS. What’s the difference between these two? Is the RS an older model of the RSS? I’m curious so if anyone has any info, please share!

Wheelock RS appliances do not have the ability to sync using a Wheelock SM or DSM module. Their intensity is also limited to 15/75 Candela (not two different intensities, just two different UL rating standards), while RSS strobes have many different Candela options and Multi-Candela available.

RS vs. RSS datasheet:

http://www.vipondsystemsgroup.com/notifier/Data_Sheet_PDFs/DN_5765.pdf

Explanation of 15/75 Candela strobes:

In the early/mid 90’s the ADA added a requirement for strobe synchronization and it was written into the NFPA 72 in 1996 so they would be aligned. After that there was a requirement that if more than two strobes can be seen in any area at the same time, they have to be synced up. This was added because strobes flashing out of sync can cause seizures in photosensitive epileptics (only a small % of epileptics suffer from this).

After that all the manufactures introduced strobes that could be synchronized either directly from a NAC power supply or via a module a notification appliance circuit passed through, and all of the un-synced devices went out of production and have slowly faded away in the field.