Build Quality
The Fellowes 9140304 is made from impact-resistant plastic with ball-bearing glides - a meaningful upgrade over the nylon-on-plastic slides used in most sub-$30 trays. The ball-bearing mechanism keeps the drawer from binding or wobbling under the weight of a full keyboard and wrist rest, and early units from 2022 through 2026 show no reported changes to the mechanism, which suggests Fellowes hasn't cheapened the design. The tray itself measures 22 inches wide by 11.63 inches deep and 2.31 inches high in its installed profile, keeping it close to the desk underside so it doesn't drop into your knees. The 4 adjustable mounting brackets are metal, not plastic tabs, which matters when you're torquing screws into a particle-board desk. Build quality is solidly above what the $36 price suggests, though it won't survive a 3-foot drop or a serious side impact.
Comfort & Ergonomics
The wrist support on the Microban-equipped variant uses memory foam, and the Microban antimicrobial treatment is a legitimate differentiator if you share a workspace or eat at your desk. Wrist support depth runs the full 22-inch width, so both hands rest on it simultaneously. The 7.5" x 7.5" mouse tray is adequate for a standard mouse but undersized for any gaming or large ergonomic mouse - a Logitech MX Master 3 at 3.1" x 4.9" technically fits, but there's no room to move it freely. The 3 height positions exist to let you dial in a neutral wrist angle, but with only 3 stops and no tilt adjustment, users outside the average height range will end up compromising. If you're under 5'4" or over 5'11" seated, expect to feel the limitation.
Adjustability
Three height positions sounds limited because it is. The Fellowes tray does not tilt, swivel, or slide forward beyond its ball-bearing track. The mouse tray mounts to the right or left edge of the main tray via a simple bracket, and it stows flat underneath when not in use - that last feature is genuinely useful if you periodically need the full 22-inch width for a larger keyboard. Height adjustments are made by repositioning the mounting brackets before final installation, not on the fly, so if your posture changes after install you're pulling out a screwdriver. The 3M AKT150LE at $80 provides continuous height and tilt adjustment; the Fellowes does not, and that gap is real.
Assembly
Installation requires a minimum 23.5-inch clear width and 14.5-inch clear depth under the desk, with no obstructions. Four screws go into the underside of the desk through 4 adjustable brackets, and the whole process takes approximately 20 minutes if your desk surface is accessible. The brackets adjust to accommodate desk thicknesses in the standard residential and office range. There are no reported assembly failures or stripped-bracket complaints across major retailers as of 2026. If your desk has a center drawer, a cable tray mounted to the underside, or any crossbar in the clearance zone, installation becomes a problem the product manual does not solve for you.
Value for Money
At $35.67 from Walmart, the Fellowes 9140304 is the best-documented, best-built keyboard tray available at this price. Staples lists the same unit at $50.99 and Quill at $60.99, so the Walmart price is the only one that makes competitive sense. Generic under-desk trays on Amazon run $20-$30, but they use plastic glides, lack mouse tray options, and have no antimicrobial treatment. The Fellowes costs $10-$15 more and delivers meaningfully better hardware. The jump to the 3M AKT150LE at $80 buys you continuous adjustment and a more ergonomically precise setup - worth it if you have specific wrist or posture issues, unnecessary if you just need to reclaim desk space at a standard sitting height.