There are many of them online all basically the same. If you do a search for Hawg Trough measuring device I’m sure you will find them. I bought mine from Austin Kayak and it’s awesome. If you would like to make one, Ed sells the tape measure sticker in the cdc store.

Crappie.com Measuring Tape stick on decal

Hawg Trough Fish Measuring Device - AustinKayak