Yes, they're low, but you don't have to worry about scraping the air dam driving onto them.
With the front wheels sitting on these (12" pictured), I have plenty of room to put my huge 4 gallon oil collector under the car, reach in and remove the oil plug and filter (and I'm under 6' and over 200lb).
And the little bit of lift helps move the oil towards the drain hole at the back of the oil pan.
12" wide for $4 a pair.
16" wide for $6 a pair.