There are some issues with Fleshlight sleeves rubbing and eventually deteriorating.
https://discuss.eroscripts.com/t/sleeve-for-kiiroo-keon/12921/10?u=goonerscriptz
Solutions are discussed above, I ended up cutting out a thick piece of cardboard and solo cup and gluing them together to make a shield to prevent rubbing. Worked great when I did it. Upgraded to the OSR2 and highly recommend it in the long run.