Backpack concrete vibrator. Free back massage while you work!
https://www.youtube.com/watch?v=z4hWA2eu1SU
Previously:
https://www.homemadetools.net/forum/...174#post126216
https://www.homemadetools.net/forum/...306#post126907
https://www.homemadetools.net/forum/...9457#post89328
https://www.homemadetools.net/forum/...640#post118133
