The Kailh Jellyfish Y Box Switch is a linear keyboard switch for people who want a smooth, direct, and relatively calm keypress. According to the provided specifications, this switch has a 50±10 gf operation force, 1.8±0.4 mm pre-travel, 3.6±0.3 mm total travel, ≥15 gf return force, and a lifespan of up to 100 million cycles.

In simple terms: this is a linear switch without a tactile bump and without a clicky sound. It feels slightly firmer than ultra-light switches like Coco Pink, while still being easy and fast enough for gaming, office, and daily use.

Quick choice

Looking for a linear switch with 50±10 gf operation force, short 1.8±0.4 mm pre-travel, 3.6±0.3 mm total travel, low sound level, Nylon stem, PC housing, 5-pin mount, SMD LED support, and up to 100M clicks? Then the Kailh Jellyfish Y Box is a strong all-round linear choice. Need tactile feedback, clicky sound, an extra light keypress, or factory pre-lube? Another switch will probably fit better.

1. Important terms explained briefly

  • Linear: the key moves straight down without a noticeable bump or click.
  • Operation force: the force needed to actuate the switch.
  • Pre-travel: the distance before the switch registers.
  • Total travel: the full downward movement of the switch.
  • Nylon stem: a stem material that can give a different feel and sound than POM stems.
  • PC housing: polycarbonate housing, useful for lighting and a brighter character.
  • SMD LED support: suitable for keyboards with SMD RGB/LED lighting.
  • 5-pin: extra stabilizing legs for PCB-mount support.

Want to compare more options? Then also check our Kailh switches, linear switches, and tactile switches.

2. Specifications with practical explanation

  • Type: Linear
  • Operation force: 50±10 gf
  • Pre-travel: 1.8±0.4 mm
  • Return force: ≥15 gf
  • Tactile force: none
  • Total travel: 3.6±0.3 mm
  • Sound level: Low
  • Operation life: up to 100M cycles
  • Suitable for: Gaming / office
  • Stem: Nylon
  • Top housing: PC
  • Bottom housing: PC
  • Contact: Composite gold
  • Spring: Spring steel
  • Protecting cover: PC
  • Slider: POM
  • Pins: 5-pin
  • Factory pre-lubed: no
  • SMD LED support: yes

What you really notice here: the Kailh Jellyfish Y Box feels balanced. The 50±10 gf operation force is not extremely light, but it is not heavy either. That gives you more control than a 40 gf switch, without making the keypress feel tiring.

The 1.8±0.4 mm pre-travel is shorter than classic 2.0 mm, so the switch registers relatively quickly. The 3.6±0.3 mm total travel is more compact than standard 4.0 mm switches. That makes it feel more direct while still behaving like a normal linear switch.

3. How does this feel while typing?

  • Balanced linear feel: no bump, no click, and medium-light resistance.
  • Fast actuation: thanks to the 1.8±0.4 mm pre-travel.
  • More control than ultra-light linears: 50 gf feels more deliberate than 40 gf.
  • Not pre-lubed: stock feel may be a little drier than factory-lubed switches.

In simple terms: the Kailh Jellyfish Y Box feels smooth, direct, and all-round. It is not so light that accidental keypresses become constant, but it is still light enough for fast inputs.

For gaming and office use, that is a strong combination. For people who want a clear tactile bump, this switch will feel too smooth. For people who want a clicky typing feel, it will be too calm.

4. Sound in plain language

The Kailh Jellyfish Y Box has a low sound level according to the specifications. Since it is a linear switch, it does not have a clicky sound like Blue, Green, or Box Summer switches.

  • No click: calmer than clicky switches.
  • Low sound level: suitable for daily use and office.
  • Not fully silent: bottom-out and keyboard build will still be audible.
  • PC housing: can make the sound a little brighter.

For a calm build without clicky noise, this switch fits well. For whisper-quiet typing, a silent linear switch will likely be better.

5. Comparison in context

Switch Feel Sound For who
Kailh Jellyfish Y Box Balanced linear, short travel Low, non-clicky Gaming, office, and all-round use
Kailh Coco Pink Box V2 Extra light linear Low Light typists and fast inputs
Kailh Red Bean Pudding Box Light linear Low Gaming and office
Kailh Box Summer Clicky with audible feedback Loud Typists who want a clear click

Practically speaking, the Jellyfish Y Box sits nicely between light and firm. It is less sensitive than Coco Pink, calmer than Box Summer, and more direct than many classic 4.0 mm linears.

6. Who is this switch perfect for?

  • You want a balanced linear switch.
  • You want a switch for gaming and office.
  • You do not want clicky sound.
  • You want SMD LED support.
  • You want a 5-pin switch with a long rated lifespan.

7. When is it less suitable?

  • When you want tactile feedback.
  • When you want clicky sound.
  • When you want an extra light 40 gf switch.
  • When you want factory pre-lubed switches.
  • When you want a fully silent switch.

In that case, it is better to look at other Kailh switches, tactile switches for feedback, or linear switches to compare different linear options.

Conclusion

The Kailh Jellyfish Y Box Switch is a balanced linear switch with 50±10 gf operation force, 1.8±0.4 mm pre-travel, 3.6±0.3 mm total travel, low sound level, Nylon stem, PC housing, 5-pin mount, SMD LED support, and a rated lifespan of up to 100 million cycles.

It is not the best choice when you want tactile feedback, clicky sound, factory pre-lube, or a fully silent experience. Its strength is the smooth linear feel, short travel, long rated lifespan, and practical use for gaming, office, and daily keyboard builds.

Also check our Kailh switches collection to compare other switches.

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