This is a sleigh bell that produces a “jingle” sound, especially in large quantities. The simplest bells were produced using a single piece of sheet metal that was bent into a sphere. A glass marble or small ball bearing was placed inside to make it jingle.
Jingle Bells from Wikipedia
This type of bell was produced centuries ago to fasten to the harnesses of horses that pulled carriages, or sleighs. The motion would make the bells jingle. The bell would warn pedestrians that a vehicle was coming so they could step aside to avoid any collision. A sleigh would be silent in the snow and not able to stop quickly on the slick surface.