Park Tool HMR-4 Shop Hammer
The HMR-4 has a fiberglass shaft, a soft touch rubber grip, and a two-sided head steel on one side and a replaceable plastic head on the other side.
The HMR-4 is nominally 2 pounds (893 grams) and is 13.5" long (345mm). The steel striking face is about 1-3/8" diameter (35mm) in diameter. The plastic face is 1-11/16" (43mm) in diameter.
This hammer is rad. Sadly, my wife used the plastic side to hit nails, but no worries. It's replaceable!