Part I of ‘Knowing and Checking’ presents SAC, a sensitivity account of checking. Part II investigates how SAC can contribute to explaining and solving existing philosophical puzzles about knowledge. This part will not defend a particular account of knowledge. Consequently, it cannot and will not explicate the actual connections between checking and knowing. Nevertheless, SAC can be used for explaining existing puzzles about knowledge. This can be done by revealing the connections between checking and our intuitions about knowing, thereby leaving open whether our knowledge intuitions are actually right or wrong. Chapter 6 first develops the core connection between checking and intuitions about knowing. Second, it presents low-stakes/high-stakes puzzles and closure puzzles, along with existing solutions to these puzzles. Third, it discusses how SAC can explain low-stakes/high-stakes puzzles and contribute to existing solutions. Fourth, it undertakes this investigation for closure puzzles and compares the SAC-based explanation of closure puzzles to alternatives. It will be shown that our intuitions about checking and knowing can only explain some low-stakes/high-stakes puzzles, but they provide the best explanation for closure puzzles. Various existing solutions to closure puzzles, such as strict and moderate invariantism and contextualism, are compatible with the SAC-based explanation.