This all depends on which hand you primarily HOLD your phone with. The difference between lefty and righty Loopy Cases is determined by the orientation and angle of the loop.
If you typically hold your phone with your left hand, we recommend going with a Lefty case! By default, all of our cases come as a Righty version, unless otherwise specified. If you think you need a Lefty, please make sure to include an order note during checkout requesting this :)