Full Specifications
| Switch Type | Tactile / Silent |
| Stem Material | UHMWPE |
| Housing Material | Nylon |
| Spring Type | 22awg gold-plated |
| Factory Lubed | Unlubed |
| PCB Compatibility | 5-pin (PCB Mount) |
| Actuation Force | 62g |
| Bottom-Out Force | 75g |
| Pre-Travel | 2mm |
| Total Travel | 4mm |
| Sound Profile | Quiet Thud |
| Price | $5.50 per 10 switches |
Editorial Review
The Gazzew Boba U4 is what you reach for when you need tactile feedback but cannot afford to disturb everyone around you. Built on the same Nylon housing as its louder sibling the U4T, the U4 swaps the POM stem for a UHMWPE (Ultra High Molecular Weight Polyethylene) stem with integrated silicone dampeners on both the upstroke and downstroke. The result is a switch that gives you a clear tactile bump with virtually no audible sound on the bottom or top of travel.
The tactile bump on the U4 is slightly less pronounced than the U4T — it is still a meaningful tactile, not a ghost of one — but the UHMWPE stem does introduce a subtly different texture to the keypress. UHMWPE is an extremely low-friction material, which means the U4 feels silky from top to bottom, with the tactile event arriving cleanly in the middle of the downstroke.
Sound profile is best described as a quiet thud. You will hear something — no mechanical switch is truly silent — but in an office or near a sleeping partner, the U4 is dramatically quieter than any unsilenced tactile or linear. The dampening is effective without the mushy quality that plagues some silent switches.
Lubing the U4 requires caution. The silicone dampeners are pre-positioned on the stem and should not be soaked in lube. A light application of 3203 or Tribosys 3204 on the rails works well. The spring can receive a thin coat of 105 oil to eliminate any ping. Avoid 205g0 on the stem itself — it may interfere with the dampeners over time.
The U4 is ideal for remote workers on video calls, office keyboard users, students in libraries, or anyone who wants the typing satisfaction of a pronounced tactile without making enemies. It pairs best with boards that have some dampening material already, like PE foam or case foam, which further reduces any remaining sound. At the same price as the U4T, the choice between them comes down entirely to your environment.
Best Keyboards For These Switches
HHKB Professional Hybrid
A silent tactile board that complements the U4 sound dampening philosophy.
Keychron Q1 Pro
Gasket mount with good sound isolation — excellent with U4 for quiet office builds.
Mode Eighty
Premium board with silicone dampening that synergizes with the U4 quiet profile.
Similar Switches
Where This Switch Fits
At 62g actuation, the Boba U4 is lighter than its POM-stemmed sibling, the U4T (67g), a direct result of swapping to a UHMWPE stem with integrated silicone dampeners. Those dampeners are the entire point of this switch: they're what turn a normally audible tactile bump into the "Quiet Thud" sound profile listed in the spec table, at the cost of a slightly less sharp-feeling tactile event compared to an undampened switch at the same weight.
Against the Gazzew Lavender (65g, no dampeners, "Sharp Thocky Tactile"), the U4 trades a meaningful amount of sound and sharpness for genuine quietness — the two switches share a manufacturer and a Nylon-housing lineage but serve opposite priorities. Anyone deciding between this list's tactile options should treat "how loud is my environment" as the primary filter before actuation weight: the U4 is the clear pick for shared spaces, while the Lavender, T1, or Holy Panda X are better suited to a private office or a household that doesn't mind the sound.