I'm looking at a data sheet for some polyurethane potting compound /
encapsualtn.

It says its Shore A rating is 1:90 - 15:85

All the Shore durometer tables I see simply have a range of 0 to 95.
Like this one:
http://www.lumindustries.com/wp-content/uploads/2014/12/Shore-Hardness-Scales.pdf


Any ideas?
Thanks


This is the data sheet:

http://www.farnell.com/datasheets/1685361.pdf?_ga=2.137631411.2079176475.1498451642-203270231.1485772309