2026 Jayco Seismic 399

2026 Jayco Seismic 399

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Exterior Colors:

  • Year 2026
  • Make Jayco
  • Model Seismic
2026 Jayco Seismic 399

2026 Jayco Seismic 399

2026 Jayco Seismic 399

The 2026 Jayco Seismic Toy Hauler is built for adventure, offering rugged durability and high-end comfort for all-season camping. With Climate Shield™ zero-degree tested weather protection, a 35,000 BTU furnace, and double-layer fiberglass batt insulation, you’ll stay comfortable in any climate. The fully enclosed and heated underbelly ensures peace of mind even in freezing conditions. With a blend of durability, luxury, and cutting-edge technology, the 2026 Jayco Seismic Toy Hauler is ready for your next great adventure.

Features may include:

Exterior
  • 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
  • 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)
  • Pass-through storage with Slam-latch™ baggage doors
  • Under-mounted spare tire
  • Fully enclosed, LED-lighted universal docking center
Interior
  • Olympic king bed (359 & 413)
  • 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
  • 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
  • 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

Dimensions

Overall Length 45' 11" | Pin to bumper: 44' 5"
Overall Height 12' 8"
Overall Height with AC 13' 2" | With 2nd A/C: 13' 2"
Overall Width 8' 6" | With slides out: 13' 6"
Interior Height Main:8' 3" | Upper deck: 6' 4"
Awning Size Length: 21' 0" | Length 2: 11' 0"
Garage Length 13' 6"

Weights

Dry Weight, Hitch 3,370 lbs
Weight 14,950 lbs
GVWR 20,400 lbs

Capacities

Cargo Capacity 5,450 lbs
Fresh Water Capacity 106.0 gals
Gray Water Capacity 87.0 gals
Black Water Capacity 87.0 gals
LP Tank Capacity 60 lbs
Water Heater 16
Sleeping Capacity up to 8

Operational

Furnace Output 35000 BTU

Wheels & Tires

Tires, Rear Specification 215/75R17.5H

Features

Features # of outside storage compartments: 2

Product Photography