As Brian says, one of these will likely last a lifetime. It is pure silicon grease, unlike the one I bought at a hardware store that is 90%. Using it on the parts of an expensive pen, I like knowing it’s just silicon grease. A tiny amount works wonders in lubricating a tight piston in a piston filler pen. I’ve used it on vintage pens (ones bought in my youth ;) and oh, what a difference!
Truthfully, my newer pens from Goulet have yet to need any grease and that includes my Twsbis which come with their own silicon grease. Twsbi’s silicon grease is kind of watery looking. If I ever need to grease a Twsbi piston, I’ll probably use the Goulet silicon grease.
As a side note, Brian mentioned in a recent q & a that he used a bit of this product on his parents’ kitchen faucet which wouldn’t move from side to side. Neither would mine, so what the heck, I put some of the silicon grease around the part that is meant to swivel — and now it does!