If it's a 3ph I'd stay away from it, unless your fields are - and you can keep them - glass smooth. I was given one, ( with the purchase of some other equipment), and the last time I tried using it I swore the next time it was connected to my tractor would be to load or move it. If a front tire goes in a hole, the rake will come up & miss a wad of hay. Then when the rear wheel gets to the low spot, rake will dig dirt. And I couldn't get it to do anything but make a mess of some hay that had gotten washed.
At least that is MY experience with a 4-wheel rake.
I went to a carted 10-wheel I found used @ almost stole it, worked real good unless the crop is pretty thick, & it doesn't like turns. I'm now using a rotary rake I love, but it costs more.
I guess bottom line, what deadmoose said!