Tighten Loose Faucet Handle and base: Moen Faucet, Kitchen, bathroom 3/32”

3/32” is the correct size but if stripped a T10 might work Affiliate links: Tool kit for tightening larger nut https://amzn.to/3QPgI8q 3/32” https://amzn.to/49YD0fy T10 Torx https://amzn.to/44vRCj5    • Home Improvement Playlist   Allen key set affiliate link https://www.amazon.com/dp/B0CNCVX7WP/... 3/32” size works for most people according to the comments