https://www.amazon.com/dp/B07GBBCKPJ?psc=1&ref=ppx_yo2ov_dt_b_product_details

​

This thing has some weight to it. Raised edge on one side to "protect" your finger. I bought it on sale and it still is. If you are used to metric (most are), make sure you look for that version. I'm a weirdo using inches so make sure you don't buy the one in that link for a metric ruler.