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2026 Jayco Seismic 399
NewStock #78956F
Listing price
2026 Seismic 399
Other floor plans with a similar body style, feature mix, and price range, prioritizing other manufacturers and brands.
What sells people on the Jayco Seismic 399 is the combination of a serious garage and genuine living space, all wrapped into one 46-foot fifth wheel. The bath and a half is the quiet hero here, giving your crew a second toilet so the main bath stays free, and two entry doors keep foot traffic flowing between the garage and the front bedroom. It sleeps eight and carries a hefty payload, so the gear comes along without a fight. If you're shopping used, it's worth giving the plumbing, hydraulics, and finish work a close look before you buy.
Length
46 ft 9 in
Dry weight
14,950 lbs
GVWR
20,400 lbs
Sleeps
8
Many factors play into a unit's listing price and what you should pay. This guide provides a ballpark estimate, but it does not factor in your exact scenario or how different listings are equipped.
$79,995 – $112,995
This unit is ranked 7 of 56 by asking price in this group.
The listing price on this unit has changed 2 times.
See the complete price timeline and the rest of this unit's pricing insights.
Southaven RV
Southaven, MS
Sells faster than 60% of Mississippi RV dealers
Compared with 7 dealers in Mississippi
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
Other listings for this floor plan, ranked by condition, model year, distance, price, and listing quality.
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
