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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 2026-11-02 13:25 UTC, and subject to change.
A harness-to-booster seat with 2 modes: forward-facing harness 40 to 65 lb, 43.4 to 49 in; belt-positioning booster (high-back) 40 to 100 lb, 43.4 to 52 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 Cosco Finale DX 2-in-1 is a forward-facing harness seat for children 40 to 65 lb and 43.4 to 49 in. that later becomes a high-back belt-positioning booster for 40 to 100 lb and 43.4 to 52 in. It shares its manual with the Finale 2-in-1 and expires 10 years after manufacture.
The Finale DX suits a child who has outgrown rear-facing and is at least 40 lb and 43.4 in., in a family that wants a harness now and a booster later. The trade-offs are the same as the Finale 2-in-1: rethreading for harness height, removing the harness to convert, and a 50 lb lower anchor limit. Cosco lists the Finale 2-in-1 with the same limits, and both pages link the same manual, so I would choose between them on colorway and current price.
A research summary of Cosco’s published specifications and manual, read . Not a hands-on test or a crash-safety rating.
This seat covers 2 stages, and a child has to meet every limit of the stage they are in. Cosco gives it a 10-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 |
|---|---|---|---|---|
| Forward-facing harness | 40 to 65 lb | 43.4 to 49 in | Not published | Manual: do not use lower anchors for a child over 50 lb. |
| Belt-positioning booster (high-back) | 40 to 100 lb | 43.4 to 52 in | Not published | — |
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.
Cosco does not publish a width for this seat, so measure your back seat and compare it with the seat in a store before buying.
Dusk, Organic Waves, Rainbow.
The shared Finale manual allows two forward-facing installations. The lower anchor belt with the tether is for children up to 50 lb. The vehicle lap belt or lap and shoulder belt with the tether covers children up to 65 lb. The tether must always be attached when anchors are available, and the lower anchor belt is never used together with a vehicle belt. The vehicle seat back must be upright, though you may adjust its angle slightly to match the car seat. The child's ears must be below the top of the seat, and the straps must sit at or slightly above the shoulders.
Source: Cosco Finale 2-in-1 and Finale DX 2-in-1 user guide (PDF)
To convert, the manual says to remove the harness system and store the buckle under the shell. LATCH is not used in booster mode, and the lower anchor belt and tether go to their storage points. Place the booster flush against an upright vehicle seat back. The lap belt goes under both armrests and lies across the upper thighs, not the stomach. The shoulder belt goes only under the armrest on the buckle side and lies centered on the edge of the shoulder, away from the face and neck. The child's ears must stay below the top of the headrest, with at least 5 in. between the head and the roof.
Source: Cosco Finale 2-in-1 and Finale DX 2-in-1 user guide (PDF)
The shared manual says the cup holder clips onto the end of an armrest and is top-rack dishwasher safe. To wash the pad, you must first remove the harness system, then release the elastic straps from the tabs on the back of the shell. Machine wash the pad separately in cold water on a gentle cycle with no bleach, and tumble dry it separately for 10 to 12 minutes on low heat, removing it immediately. Harness straps, the buckle and the shell are spot cleaned with warm sudsy water and a damp cloth, and the buckle must not be submerged. When the harness goes back in, the adjustment strap must sit behind the harness strap.
Source: Cosco Finale 2-in-1 and Finale DX 2-in-1 user guide (PDF)
No campaign in the current NHTSA child-restraint data names this model family, and I have not run a separate review for it. Check your seat’s model number and date of manufacture before use.
Cosco lists the forward-facing harness for 40 to 65 lb and 43.4 to 49 in., and the belt-positioning booster for 40 to 100 lb and 43.4 to 52 in.
Cosco Finale DX 2-in-1 Booster Car Seat product page (opens in a new tab)
Cosco lists the Finale 2-in-1 with the same limits, 40 to 65 lb and 43.4 to 49 in. in harness mode and 40 to 100 lb and 43.4 to 52 in. as a booster. Both pages link the same manual, and Cosco does not publish a functional difference beyond the colorways.
Cosco Finale 2-in-1 Booster Car Seat product page (opens in a new tab)
The manual says not to use it more than 10 years after the date of manufacture shown on the label on the side of the seat.
Cosco Finale 2-in-1 and Finale DX 2-in-1 user guide (PDF) (opens in a new tab)
With the internal harness, yes, on a forward-facing aircraft seat with the lower anchor belt and tether stored. As a booster it is not certified for aircraft use, because aircraft seats have no shoulder belts.
Cosco Finale 2-in-1 and Finale DX 2-in-1 user guide (PDF) (opens in a new tab)
Yes. The manual says to keep the booster securely belted even when unoccupied, because an unsecured booster could injure occupants in a crash or sudden stop.
Cosco Finale 2-in-1 and Finale DX 2-in-1 user guide (PDF) (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 |
|---|---|---|---|---|
| Finale DX 2-in-1 Booster Car Seat (this seat) | 100 lb | — | — | 10 years |
| Finale 2-in-1 Booster Car Seat | 100 lb | — | — | 10 years |
| Pronto! Trend Belt-Positioning Booster Car Seat | 100 lb | — | — | 10 years |
| Rise LX Booster Car Seat | 100 lb | — | — | 10 years |
| Topside Booster Car Seat (BC214) | 100 lb | — | — | 10 years |
| Topside Booster Car Seat (BC030) | 100 lb | — | — | — |
Other harness-to-booster seats whose published weight and height limits overlap the Finale DX 2-in-1 Booster Car Seat.
| Mode | Weight | Height |
|---|---|---|
| Forward-facing harness | 40–65 lb | 43.4–49 in |
| Belt-positioning booster (high-back) | 40–100 lb | 43.4–52 in |
$49.97Price on coscokids.com as of 2026-10-07 05:43 UTC, subject to change
| Mode | Weight | Height |
|---|---|---|
| Forward-facing harness booster | 40–65 lb | 43.4–49 in |
| Belt-positioning booster (high-back) | 40–100 lb | 43.4–52 in |
$79.99Price on safety1st.com as of 2026-10-07 05:49 UTC, subject to change
| Mode | Weight | Height |
|---|---|---|
| Forward-facing harness booster | 40–65 lb | 43.4–49 in |
| Belt-positioning booster (high-back) | 40–100 lb | 43.4–52 in |
$87.99Price on safety1st.com as of 2026-10-07 05:49 UTC, subject to change
| Mode | Weight | Height |
|---|---|---|
| Forward-facing harnessfrom 2 years | 30–65 lb | 35–49 in |
| Belt-positioning booster | 40–120 lb | 44–63 in |
$359.99Cool Flow Gray · Amazon price as of 2026-11-02 13:24 UTC, subject to change
