Specs for 2026 Jayco - Seismic
Floorplan: 399 (Toy Hauler)

General

Dimensions

Weights

2026 Jayco Seismic RVs for Sale Near You

Capacities

Exterior

Electrical

Features

Standard Exterior Equipment:
102 in. wide-body structural steel I-beam construction
Stronghold VBL™ aluminum-framed and vacuum-bond laminated gel-coated fiberglass exterior walls and slide room end walls
Magnum Truss™ XL6™ Roof System (strongest tested roof in the industry) with Alpha roof membrane system (limited lifetime warranty)
Painted fiberglass front cap with clear coat and built-in specialty LED lighting
Custom automotive-grade vinyl exterior graphics package
Climate Shield™ zero-degree tested weather protection includes:
35K 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)
NPS – Powered by Yamaha® 6,000-watt generator with built-in pure sine inverter (gas/C.A.R.B. certified)
6-point hydraulic auto-leveling system
Battery disconnect switch
Detachable shore power cord
Dual 30 lb. propane bottles with auto regulator
Water heater bypass
LP quick-connect
Exterior marine-grade speakers
Digital TV antenna
Folding roof ladder
LED exterior lighting package
JaySMART™ (Safety Markers And Reverse Travel) LED lighting (patented)
HELIX Cooling System™ (industry exclusive) includes:
Three exterior-mounted 13,500 BTU soft-start, high-efficiency, ducted A/Cs (living room and bedroom)
Directional and closeable A/C vents
Insulated dual-duct design
Pass-through storage with Slam-latch™ baggage doors
Under-mounted spare tire
Fully enclosed, LED-lighted universal docking center with:
Black tank flush
Winterization and sanitation hookups
Quick-connect outside shower
Satellite prep

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

Customer Value Package (Mandatory):
On-demand tankless hot water heater
50-amp service
Overlander II Solar Package: 30-amp solar controller with (2) roof-mounted 200W solar panels and a 1,800W inverter
17 cu. ft. 12V refrigerator
30 in. space-saver microwave
Residential 21 in. oven with three burners
4K Smart LED HDTV with fully digital HDMI® output
Touch-screen Bluetooth® stereo with four speakers
Electric patio awning with integrated RGB LED lights (multi-color with remote control)
MORryde® strut-assisted fold-away entrance steps (main entrance)
Custom black, machined aluminum rims
SpartanLync™ Tire Pressure Monitoring System (TPMS)
Keyed-Alike™ lock system
Bathroom power vent
Night roller shades
Hidden hinges and magnet door catches on cabinet doors

5 Star Handling Package (Mandatory):
17.5 in., 16-ply “H” rated Cooper® tires
Dexter® axles with ABS and Tow Assist – includes Nev-R-Adjust® brakes and E-Z Lube® hubs
MORryde® CRE-3000™ Suspension System
Rota-Flex® king pin
Wet bolt fasteners, bronze bushings, and 4K lb. leaf springs
2nd electric patio awning with integrated RGB LED lights (multi-color with remote control)

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
Three-season removable garage wall/doors
Tuff-ply™ rubberized garage floor liner
Rear ramp door and patio with anti-slip, non-skid flooring
Ramp patio kit with exterior steps
Rear electric patio awning
LED high-intensity ramp lights
Ram air vents and power roof vent