This is a blade for a manual mixer.
People working with these manual mixers are for sure familiar with this issue, when a mixer blade suddenly breaks. A new mixer needs to be bought to have again full mixing performance. It can be costly, if this issue happen more than admissible.
Now, thanks of 3D printing, there is no need to buy the new expensive mixer! A new blade can be 3D printed and that just for a fraction of price of the new mixer. The material cost is just about 0.50€.