I have one out of the packet but un-trimmed and it weighs 18g.
I also have a very standard Dunlop replacement grip and that weighs 17g. I would say 17/18g is about as light as you can get. What tends to happen is the the thinner grips are firmer and therefore more dense in material which more or less evens up the balance.
Once installed and trimmed to fit, I have found a standard synth grip that weighs 17/18g to reduce the static weight upon removing leather (Wilson premium) by 9g.
"Tennis is just chess with balls."
Sometimes: Dunlop Biomimetic 300 - Sometimes: Prince Exo3 Graphite 93