FROG Leap Torpedo Pacs come pre-filled with chlorine and easily inserts into the Anti-Bac Mineral Pac, dispensing low levels of chlorine for up to 3 weeks. With precise feeding, chlorine lasts 2x longer as you only need a 0.5-1.0 ppm level. The handles on the Torpedo Pac are easy to remove and you will never have to touch messy chemicals again!