Lots of neat stuff, really. It’s going to collect some “boring safe typical Martian sand that you find in dunes” and then clean its instruments with the sand. This has an equal benefit of giving them sand to analyze, too.

How’s it going to do this? Well, it’s going to use a tool at the end of its seven-foot-long robotic arm to scoop up four spoonsful of sand to run through a vibrating cylinder which will disperse the sand throughout the “hand” at the end of the arm. At 8 Gs of force!

There’s a nifty cutaway drawing of the “hand” at the link.