The K3 Custom Frame Kit comes complete with 3.5 Inch deep Stretcher Bars, Braces, Cross Braces, Corner Keys, Brace Keys, and a detailed set of instructions. Custom Frame Kits were never this easy until now! The kit is easily assembled into very strong frame ready to accept the canvas of your choice. Canvas is not included. The Professional K2 3.5 Inch deep Stretcher Bar are milled from solid fir, not finger-jointed wood which tends to break under pressure. Braces are keyable, so if you expand the frame to adjust the tension level of the canvas. And when you key out the frame, you also need to key out the braces, otherwise the frame will sag in the middle. Our professional system is unique to all other systems, and allows you to also key out the braces thereby preventing the Bars from sagging in the middle. The patented double-key Stretcher Bar system makes the frame rock solid, and won't twist. Add beauty and intrigue to your art by painting on a deep canvas.