This is silicone grease for those of you who like to fill our pens via eye dropper / syringe. For instructions on applying this grease, visit our How To page under the Info top bar tab, and reference the second video. Included in this jar is approx 1/2 oz of silicone grease. We recommend that you use this particular grease, or one marked "food grade" silicone grease, as there are many options on the market that aren't sufficient for blocking ink travel through threads. (note: jar type may vary)