I think it’s beeswax? The one I got came with some kind of wax, another pill stuffer and something else?

https://www.amazon.com/Capsule-Machine-Accessory-Sealing-Capsules/dp/B076Z4MF9X/ref=mp_s_a_1_1?keywords=capsule+connection+sealing+kit&qid=1565730226&s=gateway&sr=8-1