MINNICH CONCRETE VIBRATORS
Gas-powered back pack concrete vibrators include a new 50-cc and an updated 35-cc unit, both powered by Honda engines. A fully adjustable harness is designed to reduce strain and fatigue. The throttle assembly has a quick disconnect for changing the core/casing. It is part of the core/casing, which enables operators to use both hands to lower and lift the vibrator into and out of concrete, and locks to further enable operators to move their hands up and down the core/casing.
SOURCE: https://www.constructionequipment.com/minnich-concrete-vibrators