COMP Cams valvetrain organizer trays are perfect for novice and professional engine builders alike. These durable polymer trays neatly store your valvetrain components while you're assembling or rebuilding your engine. The organizers are labeled, front and rear, to help keep track of your part location for reassembly. Each tray has built-in handles to make easy work of moving parts around your shop or garage. They come available for valve springs or rocker arms.