New 2025 Jayco Seismic 399T

Standard Features (2025)

Standard Exterior Equipment

• 102 in. wide body structural steel I-beam construction
• NPS – Powered by Yamaha 6,000 watt generator, gas/C.A.R.B certified
• 6-point hydraulic auto-leveling system
• Battery disconnect switch
• Climate Shield™ zero-degree tested weather protection:
  • PEX plumbing
  • 35,000 BTU output furnace
  • Double layer fiberglass batt insulation in ceiling and floor
  • Double sided radiant barrier insulation (roof and floor)
  • Fully enclosed and heated underbelly (ducted)
• Custom automotive-grade vinyl exterior graphics package
• Detachable shore power cord
• Digital TV antenna
• Dual 30 lb. propane bottles with auto regulator
• Exterior marine-grade speakers
• Folding roof ladder
• Fully enclosed, LED-lighted universal docking center:
  • Black tank flush, winterization and sanitation
  • Quick-connect outside shower
  • Satellite prep
• HELIX Cooling System™ (industry exclusive):
  • Directional and closeable A/C vents
  • Jayco-exclusive insulated dual duct design
  • Two exterior-mounted 15,000 BTU ducted A/Cs (living room and bedroom)
• JaySMART™ (Safety Markers And Reverse Travel) LED lighting (patented)
• LED exterior lighting package
• LP quick-connect
• Magnum Truss™ Roof System (strongest tested roof in the industry) with Alpha roof membrane system with limited lifetime warranty
• Painted fiberglass front cap with clear coat and built-in specialty LED lighting
• Pass-through storage with Slam-latch™ baggage doors
• Stronghold VBL™ aluminum framed and vacuum bond laminated gelcoated fiberglass exterior walls and slide room end walls
• Under-mounted spare tire
• Water heater bypass

Interior Equipment

• 12V charging station
• 5/8 in. tongue-and-groove joined plywood main floor decking and 3/8 in. tongue-and-groove plywood in the roof
• Bathroom skylight
• Carbon monoxide and LP detector
• Central command center with built-in tank monitoring
• Custom interior design - Vintage Farmhouse
• Gas-strutted under-bed storage
• Handcrafted and glazed doors, drawers and trim
• Hardwood safety handrail on steps
• Heavy-duty, 75 lb., full-extension, steel ball-bearing drawer guides
• Inverter pre-wire
• LED fireplace with electric space heater (select models)
• LED interior lighting throughout
• No in floor heat registers throughout the coach
• Porcelain foot flush toilet
• Residential "Do it all" sink with pull-out kitchen faucet, glass rinse and vegetable rinse
• Residential finished dove tail jointed drawers throughout
• Residential quilted bedspread
• Residential vinyl flooring (made in the USA)
• Solid hardwood cabinet doors
• Stain protected fabric on all furniture
• SuperSofa with heat, massage and LED lighting (select models)
• Vinyl flooring in slideouts (no carpet)
• Washer/dryer prep

Customer Value Package (Mandatory)

• 16 gal. gas/electric DSI water heater
• 17 cu. ft. 12V refrigerator
• 2nd electric awning
• 30" space saver microwave
• 4K Smart LED HDTV with fully digital HDMI® output
• 50-amp service and 3rd A/C prep
• AM/FM/CD/DVD/Bluetooth® stereo with 4 speakers
• Bathroom power vent
• Custom machined aluminum rims
• Electric awning with RGB LED lights and remote control
• Hidden hinges on cabinet doors
• Keyed-Alike™ lock system
• MORryde® strut-assisted fold-away entrance steps (main entrance)
• Night shades
• Residential 21" oven with three burners
• Residential king (72 in. x 80 in.) mattress with under bed storage
• Rooftop and ground solar prep

4 Star Handling Package (Mandatory)

• 5 in. 16 ply 'H' rated Uniroyal tires
• Dexter® Axles with ABS and Tow Assist - includes Nev-R-Adjust® brakes and E-Z Lube® hubs
• Rota-flex king pin
• Wet bolt fasteners, bronze bushings and 4,000 lb. leaf springs

Ramp and Cargo Equipment

• 30 gal. fuel tank with timer
• Garage D-rings mounted to steel frame
• HappiJac® electric-lift queen beds/convertible sofas with folding armrests and cup holders
• LED high-intensity ramp lights
• Ram air vents and power roof vent
• Ramp patio kit with exterior steps
• Rear electric patio awning
• Rear ramp door and patio with anti-slip, non-skid flooring
• Three seasons removable garage wall/doors
• Tuff-ply, rubberized garage floor liner

Options

• Frameless dual-pane tinted safety-glass windows
• Outside Halo griddle for outside kitchens or JayPort system (includes LP quick-connect) (select models)
• Overlander 2 Solar Package: 30-amp solar controller with (2) roof-mounted 200W solar panels and a 1800W inverter
• Overlander 4 Solar Package: (4) 200W solar panels, (2) 100-amp/hour lithium heated batteries, 60-amp controller, 3000W inverter, DC/DC power converter, soft start power save main 15K A/C, soft start power save for bedroom 15K A/C, battery monitor, energy management system, roof pre-wire for additional solar panels, generator prep capable and heavy gauge steel battery enclosure
• Queen residential foam-top mattress

Please see us for a complete list of features and available options!

All standard features and specifications are subject to change. 

All warranty info is typically reserved for new units and is subject to specific terms and conditions. See us for more details. 

Due to the current environment, our features and options are subject to change due to material availability.