Kelim (כלים, literally "Vessels") is the first tractate in the Order of Tohorot in the Mishnah. It contains thirty chapters, making it the longest tractate in the entire Mishnah. The Tosefta on Keilim consists of twenty-five chapters, divided into Bava Kama ("First Gate"), Bava Metzia ("Middle Gate"), and Bava Batra ("Final Gate") of Keilim. The tractate discusses the laws of ritual purity and impurity pertaining to all types of vessels.
Chapter 1 clarifies the ranking of ritual impurities