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CERTAIN CONTENT THAT APPEARS ON THIS SITE COMES FROM AMAZON. THIS CONTENT IS PROVIDED ‘AS IS’ AND IS SUBJECT TO CHANGE OR REMOVAL AT ANY TIME.
Price on Amazon.com as of 2026-11-01 16:24 UTC, and subject to change.
An infant car seat with one mode: rear-facing harness (infant carrier) 4 to 30 lb, up to 32 in.
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CERTAIN CONTENT THAT APPEARS ON THIS SITE COMES FROM AMAZON. THIS CONTENT IS PROVIDED ‘AS IS’ AND IS SUBJECT TO CHANGE OR REMOVAL AT ANY TIME.
The Safety 1st onBoard Slide DLX is a rear-facing-only infant carrier for babies from 4 to 30 lb and 32 inches or less. Its SafetySlide base installs with rigid LATCH connectors or a vehicle belt and lock-off, then slides toward the door for loading. It can be belted in without the base and expires 8 years after manufacture.
The Slide DLX suits parents who find leaning into the back seat hard, because the base slides out (Safety 1st says a maximum of just under 8 inches) while the carrier goes on and off. The trade-off is a rule you must follow every time: the slide has to be pushed back and locked before driving. Against the plain onBoard Slide, the shared manual and pages describe the same base, and the DLX page adds an extra-large canopy with a zipper extension and a faux-leather handle grip.
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 | Rear-facing only |
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.
Hailstone, Dusty Marble, Dusty Green.
With the base installed, you squeeze the slide handle on the side and pull the slide toward you, then push it back until it locks. The manual says to confirm the lock by checking that the slide indicators are green and by pushing and pulling the slide to make sure it does not move. If an indicator is red or the slide moves, it is not locked. The unlocked position is only for placing or removing the carrier and placing or removing the child, and the manual says not to leave it unlocked while the vehicle is moving.
For rigid LATCH, you extend each connector, line them up with the lower anchors and push the base back until both attach. The connectors ratchet into the base, and a green indicator on each release button confirms the connection. For the vehicle belt, you open the lock-off, route the belt, lock a switchable retractor, tighten, then close the lock-off. Both tension indicators should turn fully green. If red still shows or the lock-off cannot close, the manual says to use rigid LATCH or install the carrier without the base. Never use both methods together.
The manual says on select models you unzip the canopy to extend it and open a peek-a-boo screen. Head and body pillows (on select models) must be used together and must not cover the face. The seat pad set is machine washed separately in cold water on a gentle cycle without bleach, then tumble dried separately for 10 to 12 minutes on low heat. The canopy is hand wash only and line dried. Harness straps and the shell are spot cleaned, and the buckle is not submerged.
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.
Safety 1st says SafetySlide slides out a maximum of just under 8 inches on either side of the car, even from the middle seat. The distance varies with the width of the vehicle's back seat.
Safety 1st onBoard Slide DLX Infant Car Seat product page (opens in a new tab)
The manual lists 4 to 30 lb (1.8 to 13.6 kg) and 32 inches or less, rear-facing only. The carrier is outgrown when the child reaches either limit or no longer meets the fit requirements.
Safety 1st onBoard Slide and Slide DLX manual (PDF) (opens in a new tab)
The manual says it is certified for aircraft use when used with the internal harness. On the plane you follow the vehicle belt installation 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 product page says it is compatible with all Safety 1st modular and traditional strollers to become part of a travel system.
Safety 1st onBoard Slide DLX Infant Car Seat product page (opens in a new tab)
The onBoard Slide page lists the same 4 to 30 lbs., less than 32", just under 8 lbs. and SafetySlide base. Its description does not mention the extra-large canopy with zipper extension or the faux-leather handle grip that the DLX page describes.
Safety 1st onBoard Slide 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 DLX 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 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 DLX 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 2026-11-01 16:24 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 2026-11-01 16:24 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 |
