Kailh Box Jellyfish Y 50g

Quick Summary

The Kailh Box Jellyfish Y is the linear member of the Jellyfish family: a ~50g BOX switch in a full polycarbonate housing with a bright, clacky voice and the eye-catching translucent look the line is known for. It is light, stable, and poppy, a budget linear for anyone who likes a sharper, more energetic sound rather than a deep thock.

Specs and Feel

Travel is the BOX standard: about 1.8mm pre-travel and 3.6mm total, with a medium-light 50g actuation on an 18mm stainless spring. The shorter spring keeps the press feeling light and quick. The POM BOX stem rides in a full polycarbonate top and bottom housing, and that all-PC construction is the direct cause of its clacky, high-pitched tone. There is no nylon to warm it up. The BOX rails keep wobble low and stability good. Stock smoothness is respectable with a faint polycarbonate texture under the stroke.

Tuning

It is usable stock but rewards a quick hand-lube. A thin 205g0 pass on the rails clears the slight texture and gives the clack a fuller, richer ring. The 18mm spring rarely pings, so spring lube is optional. Films are unnecessary thanks to the tight BOX housing. This is a cheap switch that punches above its price after ten minutes of lubing.

Verdict

Buy the Box Jellyfish Y if you want a light, clacky, good-looking polycarbonate linear on a budget. It is good for a bright, poppy build. It sounds sharper and more energetic than the warmer, more balanced Box Black, and it is the smooth alternative to the tactile Jellyfish. Skip it if you prefer a deep, muted thock; the all-PC housing is built to be bright, not mellow.