Guess This Tool, Win a Tool

Tell us what this is and win a Stanley Fatmax tape measure

Guess What This Is: #9
Vin Marshall

A new year, new obscure tools, and more stuff to give away. The last installment of our contest proved way too easy, so let's see if this one is a bit more of a challenge. Tell us in the comments what this is and the first and most precise answer will receive a Stanley FatMax tape measure.