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An infant car seat with one mode: rear-facing harness (infant carrier) 4 to 30 lb, up to 32 in.
$269.99on safety1st.com, as of 2026-10-07 05:49 UTC. Prices change.
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The Safety 1st onBoard Slide is a rear-facing-only infant carrier for babies from 4 to 30 lb and 32 inches or less, sharing its manual with the Slide DLX. The SafetySlide base installs with rigid LATCH or a vehicle belt and lock-off, then slides toward the door for loading. It expires 8 years after manufacture.
The onBoard Slide suits parents who want the sliding base without the DLX extras. Its page lists the same limits, carrier weight and base features as the Slide DLX, and the two share one manual, so the visible differences are the DLX's extra-large canopy with a zipper extension and its faux-leather handle grip. As with the DLX, the slide must be pushed back and locked before every drive.
A research summary of Safety 1st’s published specifications and manual, read . Not a hands-on test or a crash-safety rating.
This seat covers one stage. Safety 1st gives it a 8-year life from the date of manufacture, so check the date label before using a hand-me-down.
| Mode | Child weight | Child height | Minimum age | Conditions |
|---|---|---|---|---|
| Rear-facing harness (infant carrier) | 4 to 30 lb | Up to 32 in | Not published | Page: less than 32 in |
A child must meet every limit for the mode they use. The labels on your seat and its manual are the final word.
Every install is a fit between one seat and one vehicle. Read both manuals, and use a free inspection station if anything is unclear.
Safety 1st does not publish a width for this seat, so measure your back seat and compare it with the seat in a store before buying.
Basalt Stone.
The product page links the onBoard Slide DLX manual, and that manual's cover names both the onBoard Slide and the onBoard Slide DLX. It covers both base installs: rigid LATCH with a green indicator on each connector button, and a vehicle belt with a lock-off and two tension indicators that must turn fully green. The manual also covers installing the carrier without the base with a lap or lap/shoulder belt. Parts listed include a locking clip, which the manual requires with an emergency locking retractor and a sliding latch plate.
You squeeze the slide handle on the side of the base and pull toward you, then push the slide back until it locks. The manual says to check that the slide indicators are green and to push and pull the slide to be sure it does not move. If an indicator is red or the slide moves, it is not fully locked. The unlocked position is only for attaching or removing the carrier and placing or removing the child, never while the vehicle is moving.
The product page lists 4 harness heights for children from 4 to 30 lbs. and less than 32", a harness that adjusts from the front with a simple pull, a buckle that adjusts for length and position, and head and body inserts that come out as the baby grows. The base height adjusts for the car, and the slide reaches a maximum of just under 8" on either side, depending on the width of the back seat. The page also lists a machine-washable, dryer-safe seat pad and compatibility with all Safety 1st modular and traditional strollers.
Source: Safety 1st onBoard Slide Infant Car Seat product page
Each campaign naming this family was read against this model’s numbers and build dates, and none covers it. Still check your seat’s model number and date of manufacture before use, especially on a used seat.
The shared manual lists 4 to 30 lb (1.8 to 13.6 kg) and 32 inches (81.3 cm) or less, rear-facing only. The seat is outgrown when the child reaches either limit or no longer meets the rear-facing fit requirements.
Safety 1st onBoard Slide and Slide DLX manual (PDF) (opens in a new tab)
Safety 1st describes the carrier as just under 8 lbs. No exact figure or base weight is published on the page.
Safety 1st onBoard Slide Infant Car Seat product page (opens in a new tab)
The shared manual says it is certified for aircraft use when used with the internal harness, installed by following the vehicle belt steps without the base.
Safety 1st onBoard Slide and Slide DLX manual (PDF) (opens in a new tab)
The manual says not to use it more than 8 years after the date of manufacture.
Safety 1st onBoard Slide and Slide DLX manual (PDF) (opens in a new tab)
The DLX page lists the same 4 to 30 lbs., less than 32" and just under 8 lbs., and adds an extra-large canopy with a zipper extension and a faux-leather handle grip. If those extras do not matter, the base the two pages describe is the same.
Safety 1st onBoard Slide DLX Infant Car Seat product page (opens in a new tab)
Answers refer to the model and manual version on this page. Check the instructions supplied with your seat.
| Model | Top child weight | Seat weight | Width | Usable life |
|---|---|---|---|---|
| onBoard Slide Infant Car Seat featuring SafetySlide Base (this seat) | 30 lb | — | — | 8 years |
| onBoard FLX Infant Car Seat | 30 lb | — | — | 8 years |
| onBoard Insta-LATCH DLX Infant Car Seat | 30 lb | 7.5 lb | — | 8 years |
| onBoard Insta-LATCH Infant Car Seat | 30 lb | — | — | — |
| onBoard Slide DLX Infant Car Seat featuring SafetySlide Base | 30 lb | — | — | 8 years |
| Dreamride Infant Car Bed | 20 lb | — | — | 8 years |
| Light 'n Comfy Infant Car Seat | 30 lb | — | — | 8 years |
| onBoard LTX Infant Car Seat | 30 lb | — | — | — |
Other infant seats whose published weight and height limits overlap the onBoard Slide Infant Car Seat featuring SafetySlide Base.
| Mode | Weight | Height |
|---|---|---|
| Rear-facing harness (infant carrier) | 4–30 lb | Up to 32 in |
7% off$124.99List price $134.99Wisteria Lane 2 · Amazon price as of 2026-11-02 09:13 UTC, subject to change
| Mode | Weight | Height |
|---|---|---|
| Rear-facing harness (infant carrier) | 4–30 lb | Up to 32 in |
$199.99Beach Rose · Amazon price as of 2026-11-02 09:13 UTC, subject to change
| Mode | Weight | Height |
|---|---|---|
| Rear-facing harness (infant carrier) | 4–30 lb | Up to 32 in |
$124.00Price on safety1st.com as of 2026-10-07 05:49 UTC, subject to change
| Mode | Weight | Height |
|---|---|---|
| Rear-facing harness (infant carrier) | 4–30 lb | Up to 32 in |
