The 911MPEJAC34CE is a 3″ x 4″ Rock Crusher that will crush to 50 minus 1 4″ It is easily adjustable closed side setting goes from 3 8″ to 1 5″ With a 375 RPM overhead eccentric and equipped of a 2 5 HP electric motor this small primary rock crusher breaker will quickly have your hard rocks crushed to under 1 4″ and be ready for secondary crushing