Body Tempering, more commonly known as Instrument Assisted Soft Tissue Mobilization (IASTM), is a myofascial release technique.
It’s similar to foam rolling but instead of laying on the roller you have a weighted implement roll over you. Kind of like a giant rolling pin.
A Body Tempering tool I love to use on myself, clients, and athletes is the Boomstick. There are other tools out there but I find this the most versatile.