The 2027 Jayco Seismic 399 Toy Hauler Fifth Wheel is engineered for serious adventure, combining rugged capability with elevated residential comfort. At 45'2" with 3 slide-outs and a 21,000 lb. GVWR, it's built to haul your toys and gear with room to spare, while the 102" wide structural steel I-beam frame and Magnum Truss XL6 Roof System deliver lasting durability. Climate Shield zero-degree tested weather protection, double-layer insulation, and a 35,000 BTU furnace keep you comfortable in any season. The rear ramp door transforms into a party deck with patio stairs, extending your living space outdoors, while a half bath and thoughtfully designed interior round out this go-anywhere toy hauler.

NEW 2027 Jayco Seismic 399

Hitch:

3,265 lbs.

UVW:

15,585 lbs.

Length:

45' 2"

Sleeps:

up to 8

Stock: 27-23190N   •   Location: Tulsa

KEY FEATURES

Jayco 2+3 Year Warranty

Jayco has a decades-long reputation of quality, backed by 2-year limited and 3-year structural warranty for peace-of-mind protection.

 

5-Star Handling Package

Enjoy a safer and smoother ride with 16-ply “H” rated tires, ABS and tow assist, MORryde CRE-3000 suspension system, Rota-Flex king pin and more.

 

HELIX Cooling System (3 A/Cs)

This system enhances climate control with an insulated dual-duct A/C design and directional, closeable vents for more efficient airflow throughout the coach.

 

13' 6" Garage

Take the fun with you, whether it is motorcycles, ATVs, kayaks, or other equipment, there's room for cargo here!

 

6-point Hydraulic Auto Level

Setting up camp is a breeze with this powerful hydraulic auto leveling system.

 

NPS 6,000W Generator

Reliable power is never an issue with the NPS 6,000W generator with built-in pure sine inverter.

 

 

360 TOUR

SPECS AND OPTIONS

FACTORY-ADDED OPTIONS

• USA Standards
• Customer Value Package
• Five Star Handling Package
• Tinted Safety Glass Windows
• King Bed
• Half Bath

DOWNLOAD MSRP SHEET

SPECS

• Dry Hitch Weight (lbs): 3,265
• Unloaded Vehicle Weight (lbs): 15,585
• Cargo Carrying Capacity (lbs): 5,415
• Gross Vehicle Weight Rating (lbs): 21,000
• Length: 45' 2"
• Exterior Height: 12' 6"
• Exterior Height (with A/Cs): 13' 3"
• Exterior Width: 8' 6"
• Exterior Width (with slides out): 13' 6"
• Interior Height (main): 8' 3"
• Interior Height (upper deck): 6' 4"
• Awning Length: 21' 0"
• Awning Length 2: 11' 0"
• Garage Length: 13' 6"
• Fresh Water Capacity (gals): 106
• Gray Water Capacity (gals): 87
• Black Tank Capacity (gals): 87
• Propane Unit (lbs): 60
• Sleeps: up to 8
• Water Heater: Tankless
• Furnace BTU: 35000
• Tire Size: ST215/75R17.5'H'

 

STANDARD FEATURES AND PACKAGES

STANDARD EXTERIOR EQUIPMENT

• 102 in. wide body structural steel I-beam construction
• Magnum Truss™ XL6™ roof system (strongest tested roof in the industry) with a PVC roof membrane system (limited lifetime warranty)
• Stronghold VBL™ aluminum-framed and vacuum-bond-laminated gel-coated fiberglass exterior walls and slide room end walls
• NPS 6,000W generator with built-in pure sine inverter and gas/C.A.R.B certified with remote
• Helix cooling system™ (details below)
• Climate Shield™ Weather Protection (details below)
• Painted fiberglass front cap with clear coat and built-in specialty integrated RGB lighting app controlled
• Custom, automotive-grade vinyl exterior graphics package
• JaySMART™ (safety markers and reverse travel) LED lighting
• JayPort™ outside griddle prep (standard on all floorplans without a standard outside kitchen)
• 50-amp service
• Battery disconnect switch
• Detachable shore power cord
• Digital TV antenna
• Satellite prep
• Starlink prep
• LED exterior lighting package
• LED-lighted enclosed nautilus docking station
• Dual black tank flush, winterization and sanitation station
• Quick-connect outside shower with hose and sprayer
• 5 in. fresh water drain valve
• LP quick-connect
• Pass-through storage with slam-latch™ baggage doors
• Keyed-alike™ lock system
• Under-mounted spare tire
• 6-point hydraulic leveling

STANDARD INTERIOR EQUIPMENT

• King bed (Select Models)
• Residential quilted bedspread
• P.A.P. prepped bedroom (both sides)
• Carbon monoxide and LP detector
• Central command center with built-in tank monitoring
• Removable shower head sprayer
• Solid hardwood raised panel glazed doors and drawers
• Hardwood safety handrail on hallway steps
• Heavy-duty, 75 lb., full-extension, steel ball-bearing drawer guides
• Residential finished dove-tail jointed drawers throughout
• 5/8 in. tongue-and-groove joined plywood main floor decking and 3/8 in. tongue-and-groove plywood in the roof
• USB-C 12V charging ports (multiple locations throughout)
• 12V Inverted to 110V receptacles
• LED fireplace with electric 5,000 BTU space heater (select models)
• LED interior lighting throughout
• No in floor heat registers throughout the coach
• Porcelain foot flush toilet
• Bathroom skylight
• PEX plumbing
• Water Shutoff at all faucet locations
• Residential "Do it all" sink with pull-out kitchen faucet, glass rinse and vegetable rinse
• Washer/dryer prep
• Vinyl flooring in slide outs (no carpet)
• Super sofa or theatre seats with heat, power recline and LED lighting (select models)
• Gas-strutted under-bed storage
• Stain-protected performance fabric on all furniture

RAMP AND CARGO EQUIPMENT

• 30 gal. fuel tank with locking enclosed pump and timer
• 3-season locking garage wall
• 5,000 lb. minimum breaking load garage D-rings mounted to the steel frame
• HappiJac® electric-lift queen beds with convertible sofas, folding armrests and cup holders
• Rear loft ladder
• High-intensity LED ramp lights
• Ram air vents with power roof vent
• Lift-assisted, weatherproof, anti-skid ramp door
• Powder-coated aluminum patio kit with gate and steps
• Tuff-Ply® rubberized garage floor liner
• Power ramp patio awning with LED lighting

HELIX COOLING SYSTEM™ (INDUSTRY EXCLUSIVE)

• Jayco-exclusive insulated dual duct design
• Directional and closeable A/C vents
• 35,000 BTU high-capacity furnace

CLIMATE SHIELD™ WEATHER PROTECTION

• Zero-degree tested
• Double layer fiberglass batt insulation in ceiling and floor
• Double sided radiant barrier insulation (roof and floor)

CUSTOMER VALUE PACKAGE (MANDATORY)

• 106 gal. freshwater capacity
• Residential NuvoH2O® whole-coach water treatment system with water softening and triple-cartridge filters
• 60,000 BTU on-demand tankless water heater
• (2) 60 lb. LP gas bottles
• 12V 17 cu. ft. black glass refrigerator
• 30 in. residential microwave
• 21 in. 3-burner oven
• (3) high-efficiency soft-start A/Cs
• Teak shower seat prep
• MB Quart® Bluetooth® stereo system with (2) interior and (2) exterior speakers
• 4K Smart LED HDTV
• Glass shower door
• Roller blackout nightshades
• Soft-close hidden hinges and magnetic door catches on cabinet doors
• Lumber-core-style face frames
• Triple-slide glass shower door
• Bathroom power vent
• MORryde® 4-step strut-assisted fold-away entrance steps (main entrance)
• Universal docking station with outside shower
• Factory-installed collapsible roof ladder
• Main electric awning with app-controlled RGB LED lights
• Second electric awning with app-controlled RGB LED lights
• Fully enclosed, heated underbelly (ducted)
• Overlander II Solar Package: 400W solar panel, MPPT 30-amp solar controller and 1,800W inverter

5 STAR HANDLING PACKAGE (MANDATORY)

• 17.5 in. H-rated, 16-ply tires
• Aluminum rims
• Dexter® axles with ABS, Tow Assist and sway mitigation
• Nev-R-Adjust® brakes
• Greaseable wet bolt fasteners with bronze bushings and 4,000 lb. leaf springs
• MORryde® CRE3000 suspension system
• Rota-Flex® king pin
• Backup and side camera prep
• Entry door security camera prep