HDPE is the plastic used in many household containers including gallon sized milk jugs.

Melt down about 7 milk jugs and 3 powdered lemonade containers to get enough HDPE to make my mallet head.

The handle of the mallet is made from a cherry board and adds a nice warm contrast to the plastic!

This mallet packs a punch and is quite heavy given it smaller size!  ( from the YouTube description )