Caxixis are shakers made of braided basket, which allow a variety of rhythmical accents in different sizes and combinations. Metal shakers and tubo have a more cutting, penetrating sound due to their metal design.
The sound is okay but it's nothing really special! I purchased better sounding Caxixis on eBay and they didn't feel as cheap as these. Really really poor build quality. It feels like it's going to fall apart after a couple of weeks of using.