The 2 Packs of 10 drop ins by Walex Porta-Pak RV Holding Tank Deodorizer Drop-Ins are essential accessories for campers, boaters, and anyone else looking to keep their holding tanks clean and odor-free. With a total of 20 drop-ins in each pack, these blue deodorizers are easy to use and highly effective in eliminating unpleasant smells. The Walex brand ensures quality and reliability, making these products a must-have for anyone looking to maintain a clean and hygienic living space while out on the road or on the water.