I have a Moultrie similar to that, but it's round and holds about 90 lbs. I keep it mounted to the front of the ATV and the sprayer on the back. I've had it 12 years or so and it still works fine, but it's always had issues. You pull a lever to expose 2 round holes in the bottom to let the seed fall, but they were not cut equally. One side always puts out more than the other. I've whittled on it and improved it, but the sides will never match perfectly.

It's good for slinging out wheat, but it's hard to get it accurate enough for small seed like clover. I use it anyway; sure beats doing it by hand. It works by gravity only; there is no agitator so it can be frustrating putting out fertilizer. One clump can lock it up, so I have to screen fertilizer. This is not my main planting system, but it works ok for putting out a few bags of wheat or something.