How does the harness buckle work?

Baby Jogger calls the harness buckle a “puzzle piece” buckle and it can be a bit tricky the first couple of times you use it. Press the button to release the buckle. To re-buckle it. Insert the side strap buckles into the harness buckle on both sides (in case you have removed them). Then insert the connected harness and side strap buckles into the sides of the crotch buckle.