Alvin - Instrument Tray - Plastic - 36 Inch - The Alvin Plastic Instrument Tray is white high-impact plastic. This Instrument Tray mounts easily to the front of a tabletop to keep tools and instruments readily available. Mounting screws included. Alvin is one of the primary sources for drafting supplies and drawing equipment in the country. Creative Coldsnow is a pround retailer of Alvin graphic arts, drafting and fine arts products.