Can someone tell me what these are?

I dont think there is anything close to being a safe jack, short of a floor jack. I drove a VW bus and it came with a pathetic jack. I guess it was a geared jackscrew that raised a little square rod that fit in a receiver by the offending wheel. We jacked the front up to change the blowout (that was fun too!) and a passing big rig literally blew the bus off the jack, bending it to hell and leaving us stranded for 40 minutes until another VW bus saw pity on us and stopped. We had to time the jacking to a pause in big rig traffic, which was like none on the way from Baker to Stateline, NV. Aah, jack stories.....