Every time I stepped on the tool, the downward motion automatically ejects the two core plugs from each side of the aerator. On the second row, moving in the same eight-ish inch pattern, the plug ...

Be sure to look for a plug aerator, which pulls a small cylinder ... but as a general rule expect a quality gas-powered core aerator to rent for around $65 for a half day, or $100 for 24 hours.