The phrase "kind of boots" is an idiomatic expression that refers to a specific type or variety of footwear. It can be used in various contexts, such as describing what kind of shoes someone is wearing (e.g., "What kind of boots are those?") or asking for information about a particular style of boot (e.g., "Do you have any black leather ankle boots in stock?" - "Yes, we do. What kind of boots are you looking for?").