Abstract: A system of jacking apparatus includes an extendible jack stand with a ratchet for latching it in an extended position, and a power unit which can be selectively engaged with or disengaged from the jack stand. The power unit includes a screw-driven scissors which is interposed between upper and lower plates of the jack stand for raising the jack stand.The jack stand has a ratchet plate whose lower end protrudes in an exposed location where it can be engaged by a ratchet release member in the power unit.The power unit is also independently usable as a jack, having a pivotally supported flip-top cover which can be placed over the top of the scissors for engaging and supporting a load.