close-up of children`s toys in the form of a blue bus, on a table with a leafy background

background bali blue bus cable calibration check childrens circle close closeup construction control detail electric electrical elevator engineering equipment escalator examination field form indonesia industrial industry inspection installation instrument jack leafy lift machine maintenance measurement metal metering object outlet photo plug quality reel roller rollers rope safety speed speedometer supervision supervisor supply table tablenthis taken technical technology test tool toys verification was wire wooden work workplace