Of the Terp Liquify? I bought the 1ml, its small but you dont need much, you start at 1-3 drops per Gram of Rosin. Then you can add a bit more depending on how much it breaks down, with no more than 10 drops per Gram. I only do it for myself, which is why I got the smaller one to start. If you are doing alot then obv. the 10ml would be for you.
https://760glass.com/blogs/tutorials/how-to-find-the-correct-terpene-ratio-for-cartridges, scroll down and it will show you how to determine the amount of terpines per gram you use/need.