It’s the pushmi-pullyu of bicycle tools, with two—count ‘em—different sized hexes:
(1) 5mm; and
(1) 6mm. Total is, as stated, two.
You can find similar looking wrenches online for less, but two more things:
Infuriatingly, we sell them ONLY with a rare earth magnet, for handy attachment to steel frames. If you have a carbon or aluminum frame, you can glue or tape the magnet to the frame, but – uh-oh – in the case of a carbon frame, you’d better check to see whether your particular frame is compatible with the glue or tape used to hold the magnet. It might degrade the plastic resin used to hold the layers of carbon fiber (polyester fiber baked at 2300 deg) together.