Used 2025 Jayco Seismic 399
New Castle, INWalnut Ridge Family RV
Questions about this 2025 Jayco Seismic 399
What does it cost?
Walnut Ridge Family RV lists it at $79,995.
Is it new or used?
Used. It is a 2025 model.
Is it still for sale?
Walnut Ridge Family RV’s website listed it for sale on October 31, 2026. RV Shift checks dealers’ websites about once a day, so ask the dealer to be sure.
Where is it?
At Walnut Ridge Family RV in New Castle, IN. See all 41 RVs Walnut Ridge Family RV lists on RV Shift.
How many people does it sleep?
The dealer lists it as sleeping 9.
How long is it?
45' 11", with 3 slide-outs, as the dealer lists it.
How much does it weigh?
The dealer lists a dry weight (empty) of 14,950 lb, a GVWR (the most it is allowed to weigh loaded) of 20,400 lb and a hitch weight of 3,370 lb.
What does it take to tow it?
RV Finder’s estimate: it needs a vehicle rated to tow about 16,200 lb, with a fifth-wheel hitch. That is its 14,950 lb dry weight plus 1,200 lb for water and gear, rounded up to the next 100 lb. The listing doesn’t say whether it’s a fifth wheel or a bumper-pull. RV Finder judged it as a fifth wheel from its weights: ask the dealer. RV Finder shows whether it is within your vehicle’s published rating, from the maker’s own towing guide, and checks tongue weight and payload too. Confirm your numbers in your owner’s manual and on the sticker in the driver’s door jamb. Check it in RV Finder
How do I ask the dealer about it?
Use the Check availability form on this page. Your message comes to RV Shift and we pass it to Walnut Ridge Family RV.
About this RV
Jayco Seismic toy hauler 399 highlights: • Party Deck • Queen Bed with Convertible Sofas • Overhead Garage Loft with Storage • Walk-in Shower • 60" x 80" Queen Bed • 4K Smart LED HDTV Get ready for outdoor adventures in this spacious toy hauler. Your guests will have the 13' 6" garage with queen bed with convertible sofa and a loft for added sleeping space, plus there is overhead storage for your things and a side man door to come and go easily. The main living area includes dual opposing slides with an L-shaped tri-fold sofa along the roadside and your dinette and refrigerator plus pantry in the curbside slide. Head up the steps to your front private bedroom with the dual entry bath accessible from the hall and inside the master bedroom. Here you will all enjoy a walk-in shower, toilet, and vanity with a sink, plus overhead storage. The bedroom features a third slide out housing a queen bed for added floor space, plus a full front walk-in closet, a dresser, and washer/dryer prep! One look at the Seismic toy haulers by Jayco, and you'll never go back!
Specifications as listed by the dealer
- Type
- Toy hauler
- Condition
- Used
- Year
- 2025
- Make
- Jayco
- Model
- Seismic 399
- Stock number
- 8M0241
- VIN
- 1UJCGSCV0S18M0241
- Sleeps
- 9
- Slides
- 3
- Length
- 45 ft 11 in
- Ext Width
- 8 ft 6 in
- Ext Height
- 13 ft 2 in
- Int Height
- 8 ft 3 in
- Hitch Weight
- 3,370 lbs
- GVWR
- 20,400 lbs
- Dry Weight
- 14,950 lbs
- Cargo Capacity
- 5,450 lbs
- Fresh Water Capacity
- 106 gals
- Grey Water Capacity
- 87 gals
- Black Water Capacity
- 87 gals
- Tire Size
- 17.5"
- Furnace BTU
- 35,000 btu
- Fuel Capacity
- 30 gals
- Number Of Bunks
- 1
- Available Beds
- Queen
- Refrigerator Type
- 12 Volt
- Refrigerator Size
- 17 cu ft
- Cooktop Burners
- 3
- Number of Awnings
- 3
- Garage Size
- 13 ft 6 in
- LP Tank Capacity
- 30 lbs
- Water Heater Capacity
- 16 gal
- Water Heater Type
- Gas/Electric DSI
- AC BTU
- 30,000 btu
- TV Info
- LR 4K Smart LED HDTV
- Awning Info
- 21' Electric w/LED Lights, 11' Electric, 10' Rear
- Axle Count
- 3
- Washer/Dryer Available
- Yes
- Number of LP Tanks
- 2
- Shower Type
- Walk-In Shower
- Electrical Service
- 50 amp
Features
- 102 in. wide body structural steel I-beam construction
- NPS – Powered by Yamaha 6,000 watt generator with built in pure sign inverter, 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 gel coated fiberglass exterior walls and slide room end walls
- Under-mounted spare tire
- Water heater bypass
- 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
Listing and photos: Walnut Ridge Family RV. Details come from the dealership and can change; confirm them before you buy.