Not sure, but it’s known that weight 1 is pretty gummy, and weight 5 is really viscous, like melted glue.
Where did you buy the 100cSt from?
I guess you’ll find out when you open it, maybe it’ll turn out to be Weight 1 or even Traxxas 100K depending on how well people who’ve said 50K is like 5K cst and labellers have done their research.
my 4000 cSt is thinner than melted glue. It is closer to liquid honey, which is why I got some 15.000cSt as well.
You can get many viscocities from 50-1000 cSt on the Internet, aliexpress etc. I ordered at eurorc.com - €2.99 in shipping - they also have a UK store. They have differential oil up to 2.5mio cSt, which looks like grease to me judging the container. Plummers often have Silicone grease as well. Shock Absorber oil is below 1000 cSt, all the way down to 100 cSt. My packet is still somewhere between Finland and Denmark.
I used to use hobbyking, but they do not sell oil anymore.