People have lovingly referred to the standard D4 shape as a “caltrop” due to it’s shape and pain inflicted, should you ever step on one.
Here you have a functional forged D4 in the style of a caltrop, with numbers and everything.
These are not functional caltrops and can not be used as such. The tips are rounded and are not sharp. You will have more success using a regular D4 as a caltrop.