Linear switches are a bit of an acquired taste, but the proliferation of gaming-oriented boards has acquainted many users with switches like the MX Red and MX Black. Despite not having a clicking mechanism, linears tend to produce a racket because it's easy to bottom them out on each press. A few silent linears exist to combat this, and keyboard enthusiasts are about to have a new silent linear option from Zeal PC -- it's called a Helio, and you can pre-order some now.
Helios are part of the Zeal V2 revamp, which includes new Zealios and Zilent switches as well. Those switches have different tactile bumps, but the Helio is an entirely new design based on the Tealio linear switches. They're the silent counterpart to Tealios like Zilents are the silent alternative to Zealios.
Like all linear switches, Helios continuously increase in resistance as you press with no tactile bump or click. In the first round, these switches will only come in a single 67g weight (other Zeal switches come in 62, 65, 67, and 78g). That makes Helios heavier than an MX Red but a little lighter than MX Blacks.
These are silent switches because of the distinctive stem design (which is orange to differentiate from other switches). As you might recall from a past spotlight on Zilents, silent keyboard switches have a small landing pad on the top and bottom of the stem. That silences the downstroke (hitting the bottom of the housing) and release (hitting the top). Adding o-rings to your switches is a common way to make them quieter, but that only silences the down part. Plus, it reduces travel considerably. A silent switch is a vastly better option if you are assembling a custom board.
Healios have a new generation of bumpers that should provide a more consistent typing experience. With other silent switches, the bumper is only on the middle rail of the stem (top and bottom). Helios add more two small bumpers at the bottom to give it more stability upon landing. With some other dampened switches, you can feel the pads slip a little left or right if you press down especially hard. I don't think that will be a problem with Helios. I only have one prototype switch to try, but it's very smooth and solid. I'm not a huge fan of linears, but I do like this switch.
Helios are pricier switches because, like Zilents, the stems are much more complicated. During the pre-order window, you'll pay $9 for each 10-switch pack. Equipping a small 60% board would, therefore, run you around $60. These are spendy compared to a lot of other switches, but I've never encountered a Zeal-branded switch that wasn't best-in-class.