GDHXW manufactures this product for use in the Aftermarket of airless spray pump systems from Graco Nova, Ultra, Max II 390, 395, 490, 495, and 595 models as well as LineLazer 3400 sprayers. All components are included with the pump. Please be aware that some customers do not carefully review product descriptions, leading to incorrect purchases, wasting time, and incurring high shipping costs. This product is not compatible with ST PC Por sprayers. Prior to installation, it is recommended to shake the pump multiple times to prevent the internal steel ball from adhering to the alloy plate, which could result in improper functionality. Keep in mind that this product is long-lasting and durable, but impurities in the paint may cause blockages that affect the pump's performance. Troubleshooting can be done by following the provided instructional video.