It was a solar panel, specifically. 47 had been collecting them along with other bits and pieces.

That was right, it was easier to get ammo these days. He was used to conserving his ammo for missions. But last time he hadn't had to, and this time he could just get the others to give him more. Since Tidus was offering...

"More ammo for the rifle would be the most useful." It was the most efficient against the robots.