When you receive your portable catchbox, it will be flat. To identify the 'top' or 'bottom', look for tabs to hang the catchbox on the 'top'. Also, the velcro ammo stop inside the catchbox mounts to the 'top'.
The wire in the top and bottom of the box is sewn in place. The wires for the right and left sides are free. Extend the catchbox to the open position while the opening is face up. Attach the side wires to the fixed upper wire with supplied zip ties. You only need one per side but may use more if desired.
Now you simply move the side wires into position on the right and left hand side of the catchbox. Then attach the side wire to the sewn in bottom wire with the flat ribbons sewn into the bottom seam. You may also zip tie these two wires together if you don't plan to collapse your box for storage.
Be sure to reattach the velcro ammo stop before you shoot. Suspend your chosen target in the opening of the catchbox and start shooting!