Signature cabins use only far infrared, from Sunlighten's patented SoloCarbon heaters, with push-button controls rather than programs. Sunlighten pitches it as the collection for simple, everyday sessions. Every Signature has chromotherapy lighting, a Bluetooth sound system, heater covers made with CELLIANT fabric, and Sunlighten's Magne-Seal magnetic corners, which lock the wall panels together without clips or screws.
Sunlighten's own Signature page currently shows the one- and two-person models. Its US online store also sells a three-person Signature III and a four-person Signature IV, both in the Obsidian finish: black outside, natural eucalyptus inside. Signature I is also sold in plain eucalyptus.
See the Signature at Sunlighten (opens in a new tab) All Sunlighten prices Sunlighten review
Signature at a glance
- Infrared
- Far infrared only (SoloCarbon)
- Controls
- Push-button, no preset programs
- Sizes
- 1 to 4 people
- Power
- Dedicated 120V 20A circuit for I to III; 240V for IV
- Max temperature
- Not stated by Sunlighten
Sizes and specs
- Signature I (37.8 in wide, 428 lb) fits one person on a 32 in bench and runs 8 far-infrared heaters at 1,350W.
- Signature II (50.9 in wide) seats two on a 45 in bench with 9 heaters at 2,006W.
- Signature III (62.3 in wide, 622 lb) widens the bench to about 56.6 in with 10 heaters at 2,250W, still on a 120V 20A circuit.
- Signature IV (80.9 x 56.1 in, 779 lb) has a 74.6 in bench that reclines, 10 heaters at 2,750W, and is the only Signature that needs 240V.
| Model | Type | Seats | Exterior (W × D × H) | Power | Heat |
|---|---|---|---|---|---|
| Signature I (opens in a new tab) | Infrared Cabin, indoor | 1 | 37.8 × 39.8 × 77.7 in | 120V 20A dedicated outlet NEMA 5-20, 1,350W | 8 far-infrared SoloCarbon heaters |
| Signature II (opens in a new tab) | Infrared Cabin, indoor | 2 | 50.9 × 45.9 × 77.7 in | 120V 20A dedicated outlet NEMA 5-20, 2,006W | 9 far-infrared SoloCarbon heaters |
| Signature III (opens in a new tab) | Infrared Cabin, indoor | 3 | 62.3 × 45.9 × 77.7 in | 120V 20A dedicated outlet NEMA 5-20, 2,250W | 10 far-infrared SoloCarbon heaters |
| Signature IV (opens in a new tab) | Infrared Cabin, indoor | 4 | 80.9 × 56.1 × 77.7 in | 240V 20A dedicated outlet NEMA 6-20P plug, 2,750W | 10 far-infrared SoloCarbon heaters |
Specs as each brand publishes them, checked October 2026. "Not stated" and "See brand" mean the product page does not give that figure. Models change: confirm size, wiring and price on the brand's page before ordering.
Signature prices
Prices as listed on Sunlighten's US online store on October 9, 2026, by finish. See every Sunlighten price on one page.
| Model | Finish | Seats | Power | Store price | Regular price |
|---|---|---|---|---|---|
| Signature I (opens in a new tab) | Eucalyptus | 1 | 120V 20A dedicated outlet | $4,999 | $5,499 |
| Signature I (opens in a new tab) | Obsidian (black exterior) | 1 | 120V 20A dedicated outlet | $4,999 | $5,799 |
| Signature II (opens in a new tab) | Obsidian (black exterior) | 2 | 120V 20A dedicated outlet | $5,499 | $6,399 |
| Signature III (opens in a new tab) | Obsidian (black exterior) | 3 | 120V 20A dedicated outlet | $6,399 | $6,799 |
| Signature IV (opens in a new tab) | Obsidian (black exterior) | 4 | 240V 20A dedicated outlet | $7,799 | $8,399 |
Prices from the Sunlighten US online store (shop-us.sunlighten.com), checked October 9, 2026. "Regular price" is the store's compare-at price; the gap is a promotion and changes often. Checkout discounts, shipping offers and sales tax can change the total. Confirm the price on Sunlighten's site before you order.
Add-on packages
Bundles of linens, cushions, backrests and cleaning supplies, sized to the cabin. The Ultimate tiers add Sunlighten's handheld light-therapy device, and Ultimate Radiance adds its red light therapy mask.
| Package | For | Store price | Regular price |
|---|---|---|---|
| Comfort | Signature/Amplify III (3 Person) | $549 Not available online | $649 |
| Essentials | Any cabin | $299 | $349 |
| Comfort | Signature/Amplify IV (4 Person) | $849 | $999 |
| Comfort | Signature I (1 Person) | $499 | $599 |
| Comfort | Signature/Amplify II (2 Person) | $499 | $599 |
| Ultimate Radiance | Signature I (1 Person) | $1,099 | $1,199 |
| Ultimate Radiance | Signature Amplify III (3 Person) | $1,199 Not available online | $1,299 |
| Ultimate Radiance | Signature Amplify IV (4 Person) | $1,399 | $1,499 |
| Ultimate Radiance | Signature/Amplify II (2 Person) | $1,099 | $1,199 |
| Ultimate Rejuvenation | Signature I (1 Person) | $999 | $1,099 |
| Ultimate Rejuvenation | Signature/Amplify II (2 Person) | $999 | $1,099 |
| Ultimate Rejuvenation | Signature/Amplify IV (4 Person) | $1,399 | $1,499 |
| Ultimate Rejuvenation | Signature/Amplify III (3 Person) | $1,099 Not available online | $1,199 |
From Sunlighten's US online store, checked October 9, 2026.
What it costs to run
Rated draw runs from 1,350W (Signature I) to 2,750W (Signature IV). At the July 2026 U.S. residential average of 18.31¢/kWh (EIA), an hour at full draw costs about $0.25 to $0.50.
Real sessions usually cost less, because the heaters cycle once the cabin is warm, but warm-up time adds to it. Put your own rate into the running-cost calculator.
Before you order
- All four need a dedicated circuit: 120V 20A with a NEMA 5-20 outlet for I to III, 240V 20A for IV. Sunlighten says a power strip or converter voids the warranty.
- Signature IV's store page lists a 240V 6-20P plug but also names a 5-20R outlet, which is a 120V outlet. Confirm the outlet with Sunlighten before your electrician installs it.
- Every Signature is 77.7 in tall including 2 in feet. The store says they fit under a standard 8 ft ceiling and that panels fit through a standard 30 in doorway; leave 4 in from the walls and 12 in above.
- Sunlighten does not publish a maximum temperature for the Signature. If you want a hotter, faster sweat, the Amplify is the collection Sunlighten markets for that.
Delivery, assembly, returns and warranty are the same across Sunlighten's range; they are covered in our Sunlighten review. We have not tested Sunlighten saunas and do not rate them. Specs come from Sunlighten's product pages and US store; confirm current specs and prices on Sunlighten's site (opens in a new tab).
Other Sunlighten collections
- Amplify and Amplify RED: Amplify is Sunlighten's hot one: far infrared plus halogen full-spectrum heaters, up to 170°F. Amplify RED adds red and near-infrared light panels.
- mPulse: mPulse is Sunlighten's flagship: red, near, mid and far infrared controlled separately, preset programs, a built-in tablet and an app.
- Solo System: The Solo is Sunlighten's no-room-for-a-cabin option: you lie on a heated pad under two sliding domes, head outside, and it folds away.
Frequently asked questions
What is the difference between Sunlighten Signature and Amplify?
Signature uses far-infrared heaters only with push-button controls. Amplify adds full-spectrum (halogen) heaters, thicker insulation and double-pane glass doors, and Sunlighten says it reaches up to 170°F. On the US store, a two-person Amplify II lists $300 to $500 more than a two-person Signature II (prices checked October 9, 2026).
Does the Sunlighten Signature run on 120V?
Signature I, II and III run on a dedicated 120V 20A circuit with a NEMA 5-20 outlet. Signature IV needs a dedicated 240V 20A circuit.
What is the Signature Obsidian or Black Edition?
The same Signature cabin with a black exterior and a natural eucalyptus interior. On Sunlighten's US store, Signature II, III and IV are listed only in this finish.
