It is a first-class T-Handle Hex Key with 3 heads (!!!). The handle can be moved. No cheap loosy China scrap!!
This one is one of my best tools I ever had. Don’t waste your time and money to buy Hex Key (Inbus) sets, you will always loose!
You need a 4 mm T-Handle Hex Key for the 2 screws (2 each side) to fix the stanchion tubes into to crown – all XC forks except DH3.
Available on back-order