Only concern is with the instructions / drawings. The product was delivered in 2 days and was well packed. The base frame mounting plate and mounting arm are heavy. Excellent packing resulted with all items arriving in good condition. The system is very rugged and stable. I am delighted with the product and its operation.Requirement. Replacing a sliding keyboard tray intended for table top operation. Tray was mounted under desk top, allowing no adjustment for height and tilt nor space for a mouse. Right arm was always elevated with pressure on desk edge to operate the mouse on desk. Right shoulder pain led me to pursue an under desktop keyboard tray with space for a mouse pad and tilt adjustment. Considerable time was taken to review numerous products and user reports. This 3M product was selected base on specifications, large number of positive user report and user helpful installation suggestions.Base frame mounting. Drew center line on underside of desk between to desk supports, 2 drawer file cabinets. Useable depth is 24-1/2 inches. Did not use template. Secured front of base frame to front underside of desk with a large “C” clamp. Base frame was recessed 1-1/2” from front of desk. The front of the keyboard tray protrudes about 1/2” beyond the desk edge when the tray is fully retracted. That protrusion causes no problem with my work area. As others have written, a 2” recession will provide no protrusion when the keyboard tray is stowed under the desk.First secured back of base frame to desk with screws and then front and mid span attachments. The length of the wood screws was of concern since the desk top is laminated ½” plywood. Placed a flat washer under the screw head to reduce the penetration depth. The protruded screw head and washer seemed to interfere with the travel of the mounting bracket. Installed one of the screws at the rear of the desk to test for top penetration. The screws were the perfect length for strong attachments without desk top penetration. The 1/8” pilot hole size was perfect for the attaching the screws with plenty of circumference for thread locking into the wood. Used electrical tape around the drill bit, 3/8” back from tip, as drilling stop guide.Did not attach the long wrist rest pad. Intend to use the tray tilted forward to relieve pressure on fingers and wrists with more pressure on arms. The mouse pad was not affixed to the tray. It has a slick surface. When the tray is tilted forward the mouse slides off the supplied key pad. Will install a mouse pad with a more rubberized surface to prevent mouse sliding.Another minor installation issue was with attaching the plastic stopper on the end of the base frame that faces the front of the of the desk. This cap prevents the tray from being pulled out of the base frame track. Two screws that appear to be machine screws are supplied. However the holes where they attach do not appear to be threaded. With a closer look at the screws you can see that one side of the ends is shaved to enable penetration and self threading. It is necessary to apply significant pressure on the plastic end cap to line up the holes in the cap with the holes in the base frame. The pictorial view is very small, limiting good visualization of the procedure.Greatest challenge was determining how to raise and lower the shelf. Placard on top of the mounting arm states to adjust height lift front edge of keyboard platform, set to desired height, then release platform. My thought was that the “front edge” was the edge facing me. When attempting to lift that “front” the platform would not move. Adding more pressure made it seem that the mounting screws on the frame under the desk would pop out from the immense pressure. Finally realized that the “front edge” to be lifted is the edge in front of the keyboard, next to the mounting bracket. Voila! The keyboard tray moved smoothly up and down and firmly locked into place. Found that it also helps to move the tray downward when moving to desired elevation.Possible re-installation. When starting the installation, drew the center reference line on underside of desk on center between the two side file cabinet frames. That worked fine for the previous tray that did not have a side area for the mouse. As a result of having a wide keyboard with numeric pad and mouse on the right side, I am not positioned at the center of the monitor screen when typing. It is beneficial to have the keyboard tray positioned such that when typing, the “G and H” keys are in line with the center of the monitor. The monitor has been moved as far to the right as possible without hitting the printer. There is room under the desk to move the base frame another 4 inches to the right. Next week’s project.One unexpected benefit is being able to raise the keyboard high enough to stand and type! Researchers are now stating that sitting is more dangerous than smoking, kills more people than HIV. There is now evidence that prolonged sitting increases the risk of developing several serious illnesses. Studies have repeatedly shown the effects of long-term sitting are not reversible through exercise or other good habits. So, we need to discipline ourselves to frequently take advantage of the great standing capability with this keyboard elevated.Summary. I am extremely delighted with the product’s construction, operation and features. My right arm and shoulder are feeling significantly better from having the mouse at the keyboard level and my arm supported horizontally with the chair arm. The keyboard positioning options are wonderful, including swiveling the tray to the right and left. I very strongly recommend this product to anyone. One gets what one pays for, most of the time. This product is worth its investment.My only concern is that the instruction booklet needs better explanations and illustrations of assembly and operation. The product comes with a useful base frame mounting template. A booklet has step-by-step assembly illustrations with limited explanations and small diagrams of components and interconnection.