About us

We Started Because Bad Sleep Is a Real Problem

Most people think a bad night's sleep is just bad luck — too much on their mind, the wrong mattress, a noisy street outside. What fewer people talk about is the light. The streetlight bleeding through curtains at 2 AM. The glow of a partner's phone. The too-bright morning that ends a much-needed extra hour of rest before it even starts.

That's the problem Cosyzz was built to solve.

We're a sleep products company based in St. Louis, Missouri. We sell sleep masks — but that description undersells what we actually do. What we do is take something that's been treated as an afterthought (a thin piece of fabric with an elastic band, usually an airline freebie) and rethink it from the ground up.

The Honest Starting Point

We'll be straightforward: we're not a company founded by a team of sleep scientists or ex-NASA engineers. We're a small trading company — JIANYI TRADING LLC — operating out of Missouri, and we got into this because we saw a real gap between what was available and what people actually needed.

The sleep mask market is full of products that look fine in photos and disappoint by 3 AM. Straps that dig into your ears. Masks that let in light around the nose. Silk that's sold as "luxury" but turns out to be a thin polyester blend. Foam that traps heat. One-size designs that don't actually fit most faces.

We knew we could do better. So we found manufacturing partners who could, and we got to work.

"The sleep mask market is full of products that look fine in photos and disappoint by 3 AM."

What We Actually Focused On

Before we settled on our product lineup, we spent time understanding specific complaints — not general "bad sleep," but the specific, physical reasons why sleep masks fail the people wearing them.

Side sleepers kept coming up. It turns out side sleeping is one of the most common sleep positions, and almost no sleep mask is actually designed for it. Traditional elastic straps pull on your ears when your head is pressed against a pillow. The pressure builds, you pull the mask off in your sleep without even realizing it, and you wake up with light in your face at 6 AM.

People with dry or sensitive eyes told us that flat masks pressing against their eyelids were a non-starter. Contact lens wearers. People who go to bed with light skincare routines they'd rather not ruin by pressing fabric against their face all night.

Travelers wanted something compact that wouldn't feel like a compromise — something that actually blocked light on a red-eye flight, not just reduced it a little.

These weren't edge cases. They were the majority of the market, being sold products designed for the minority.

How We Built the Collection

Our current lineup reflects what we learned. Each product exists because it solves a specific problem better than anything else in its category.

The Larger Mulberry Silk Sleep Mask came from the side sleeper problem. The key detail isn't the silk — it's the width. The mask extends further around the head, covering the ears entirely. The strap doesn't cross the ear at all. For people who sleep on their side, this is the difference between waking up with the mask on and waking up with it on the pillow next to them. The 19mm mulberry silk on both sides also does something that synthetic materials can't: it wicks moisture gently away from the skin and reduces friction, which matters for anyone conscious of sleep creases or eye-area skin.

The 3D Contoured Sleep Mask and Ergonomic 3D Sleep Mask came from a different problem: eye contact. A flat mask pressed against your eyelids is uncomfortable for a lot of people, and over hours it creates real eye fatigue. The 3D shell design lifts away from the eyes entirely, creating a small dark chamber. You can blink. Your lashes don't brush against fabric. For people with dry eyes, or people who just find the pressure genuinely uncomfortable, this design is a significant upgrade.

The Light Blocking Cotton Sleep Mask is our practical everyday option. Premium grey cotton with an upgraded nose-pad design that seals out more light than the typical mask — useful for daytime naps, travelers on a budget, or anyone who wants a reliable mask without spending a lot.

The Silk Sleep Masks 4-Pack exists because a lot of people want one for every bag, every room, every travel situation. Satin silk in four colors, priced to make stocking up reasonable.

What We Don't Claim

We're careful about what we say, because we think most product marketing oversells.

We don't claim our masks will "transform your sleep" or add hours to your night. What we claim is more specific and more honest: our masks block light effectively, they're physically comfortable for the sleeping positions and preferences we've designed them for, and they're made from materials that hold up to regular use.

That's it. No proprietary sleep technology. No clinical studies commissioned to prove our products work better than everyone else's. Just well-designed, well-made sleep masks that do what they're supposed to do.

"We think most product marketing oversells. We prefer to let the product be straightforward about what it does."

Where We Are Now

Cosyzz is a small operation. Our team is lean, our logistics are handled through established US-based fulfillment, and our customer support is reachable by email and phone — real responses, not automated queues.

We ship within the US. We offer free shipping on all orders, a 30-day return policy, and a genuine commitment to making things right when something goes wrong. If you get a mask that doesn't fit the way you expected, or that arrives damaged, contact us and we'll sort it out.

We're not a large company. We're not trying to become one by overpromising. We're trying to build a business where the product is good enough that customers come back, tell people about us, and trust what we say.

That's the whole plan.

Get in Touch

If you have a question about which mask is right for you, a problem with an order, or just want to give us feedback — we'd like to hear from you.

Email:    info@cosyzz.com

Phone:   +1 (314) 557-8660

Address: 309 Lovins Dr, Saint Louis, MO 63141, USA

Website:  https://cosyzz.com

JIANYI TRADING LLC  ·  St. Louis, Missouri