Powerscreen has improved the Powerscreen X400S jaw crusher by incorporating a fully independent high amplitude, hydraulically driven pre-screen with increased drop angle on the bottom deck to increase machine throughput and overall capacity. The pre-screen removes a large percentage of the fines within the feed material before it enters the jaw chamber, resulting in increased output from the machine.The pre-screen works effectively in applications where the feed material is dirty. The aggressive nature of the pre-screen means that the dirty material can be screened out before entering the crushing chamber. The end result is a cleaner crushed product.