The Trinity 3-IN-ONE: The Ultimate Sauna Experience

Experience it all — infrared, steam, and red light therapy — in one luxurious design. The Finnmark FD-4 Trinity Combination Sauna is the only sauna that unites UL-listed Spectrum Plus™ infrared heaters, a traditional 120V Finnish sauna stove, and medical-grade Spectrum Red Light™ Therapy for a complete wellness experience.

No compromises. Spectrum Plus™ short-wave infrared heaters heat up quickly, penetrating deep into muscles and joints to promote detoxification and deliver a sweat up to 25× more effective than standard carbon heaters.

Enjoy the authentic steam experience with the 1.9 kW traditional heater, allowing you to pour water over the rocks for that classic Finnish feel.

The Red Light Therapy system enhances your wellness routine by stimulating collagen production, improving circulation, and supporting natural healing.

With Full Spectrum technology, combining long-wave Carbon 360™ and short-wave Spectrum Plus™ panels, you’ll achieve deeper heat, superior detoxification, pain relief, and faster muscle recovery — all in record time.

Trinity 3-IN-ONE Sauna — Key Features

Discover the most advanced sauna ever created. The Finnmark Designs Trinity 3-IN-ONE combines infrared, steam, and red light therapy into one exceptional wellness experience — designed for performance, durability, and total rejuvenation.

Premium Features

  • Spectrum Plus™ UL-Listed Short-Wave Infrared Heaters
    Delivers deep, penetrating heat — up to 25× more effective than standard carbon panel heaters — for faster detoxification and muscle recovery.
  • Spectrum Red Light™ Therapy Panel
    Features 192 medical-grade diodes producing 650nm red light and chromotherapy, promoting skin rejuvenation, collagen production, and overall cellular health.
  • Antimicrobial Western Canadian Cedar Interior
    Naturally resists mold, bacteria, and fungus, ensuring a clean and safe environment with every session.
  • Thermal Plus™ Aspen Exterior
    Built to last — will never rot, warp, decay, or chip, making it one of the most durable sauna exteriors available.
  • 3-IN-ONE Combination Design
    The only sauna that combines UL-listed infrared heaters, a traditional steam heater, and medical-grade red light therapy — giving you every wellness benefit in one unit.
  • Built-in LCD Wi-Fi Touchscreen Controller with Bluetooth Audio
    Easily control temperature, lighting, and sound with intuitive smart features and 6” Hi-Fi speakers for a relaxing experience.
  • Superior Construction & Comfort
    Includes 8mm tempered glass for thermal retention, an extra-large two-tier bench system, and low EMF infrared heaters verified by a NASA award-winning testing facility.
  • Harvia Vega Compact 1900 Heater (Made in Finland)Wall-mounted stainless steel design1.9 kW output — ideal for sauna rooms from 70–106 cu. ft.Built-in ergonomic controls (right or left installation)Requires 29 lbs of sauna stones (Model AC3000); we recommend purchasing an extra box for optimal fit and performanceDimensions: 11"W x 11"D x 21"H2-Year Consumer Warranty.

Product Specifications

  • Model: FD-4
  • Exterior: Thermo-Aspen
  • Interior: Western Red Cedar
  • Voltage: 120V
  • Power: 1750W | 15/20 Amps | NEMA 5-15P Plug
  • Outlet: Standard 120V / 15A
  • Max Temperature: IR 170°F | Traditional 190°F
  • Interior Dimensions: 44.25"W × 45.5"D × 75.5"H
  • Exterior Dimensions: 48"W × 48"D × 83"H
  • Room Volume: 86 cu. ft.
  • Glass Door: 23.6"W × 68.9"H | 8mm Thick w/ Gasket
  • Weight: 437 lbs (Shipping: 618 lbs)
  • Shipping Dimensions: 80"W × 40"D × 58"H

Heater Details (Harvia Vega Compact 1900)

  • Power Output: 1.9 kW | Electric | 120V / 1PH
  • Coverage: 70–106 cu. ft. room volume
  • Amperage: 15.9A
  • Dimensions: 11"W × 11"D × 21"H
  • Weight: 15.4 lbs (59.4 lbs with sauna stones)

Add-on

Finnmark FD-4 Sauna Cover | 48″×48″×83″ Marine-Grade Waterproof Protection

The Finnmark FD-4 Sauna Cover is a premium all-season protective cover tailored to sauna cabins with a footprint of roughly 48″ x 48″ x 83″. Constructed with a waterproof Aqualon roof, marine-grade canvas sidewalls, reinforced marine-grade hardware and an accessible roll-up front door with ties, this cover shields your sauna investment from the elements while maintaining style and durability.

$1,298.00