The unit arrived in a timely fashion, I drilled 5 - 1/2" diameter holes 4" deep in a concrete foundation smooth and reasonably fast all as expected.
I gave it 3 Stars as only time will tell how long the unit will last.
Norbert
Hiouchi, CAGet more detail about Factory-Reconditioned Ryobi ZRD552HK 1/2-Inch Two-Speed Hammer Drill.
