Your coffee and phone keep taking the last usable corner of the desk. The Yamazaki Tower clamp cup holder creates a parking place beside the tabletop rather than on it. That can be a neat space-saving move, but only when the desk edge gives the clamp somewhere suitable to grip.
The underside matters as much as the top
The selected black1639 attaches with an adjustment screw. The manufacturer specifies a mounting thickness of 1.2–4cm, at least3cm of width and 4.5 cm of depth. An apron, brace or awkward edge profile can still prevent installation even when the tabletop thickness looks correct.
Measure below the desk, not just above it. Check that the chosen spot leaves your chair, knee and hand room to move. Avoid delicate or unsuitable finishes unless you have confirmed mounting will not damage them.
Match both compartments to your belongings
The cup compartment is 8.7 by 8.8 cm internally, while the phone slot is 8.7 by 2.8 cm; both are4.9cm high. A wide mug, oversized handle or thick phone case may be the real deal-breaker. The separate limits are1kg for the drink compartment and 500 g for the phone side—not1.5kg in either section.
A cable opening allows access for your own charging lead. No charger or power supply is built in. The surrounding rim is useful containment, but it cannot promise that a bumped open mug will never spill.
A good little boundary
It suits a compatible flat-edged desk where relocating two objects genuinely frees workspace. If you often bump the desk edge or carry a large bottle, a simple coaster farther from the keyboard may be wiser. The photographs illustrate manufacturer arrangements, not our own mounting or spill test.
