Sealy Baby Flex Cool 2 Stage Crib Mattress and Toddler Bed Mattress
- Cribs, Beds & Mattress
- Cotton
- Coil
- Standard Mattress
- More reviewed than 61%
A dual-stage crib mattress with a real waterproof cover and third-party emissions certification, sized for standard cribs, from a mattress maker with decades in the category.
As an Amazon Associate, ProductDome may earn a commission from qualifying purchases made through links on this page.
How it ranks among the 28 cribs, beds & mattresses we track
4.7★ across 3,000 Amazon ratings, Bayesian-smoothed toward the category average.
3,000 Amazon ratings, weighted on a log scale so huge counts don't drown everything.
700+ bought on Amazon last month.
Brand identity, imagery, description and spec coverage.
The ProductDome score is separate from the Amazon rating shown above: it combines the Bayesian-smoothed Amazon rating with evidence volume, tracked demand, and data quality across the 28 cribs, beds & mattresses we track - how the scorecard works · full cribs, beds & mattresses data report. Confidence: high - strong rating volume and complete data.Updated 3 days ago. Data-computed, not a hands-on test. Compiled by the ProductDome Research Team.
Overview
The Sealy Baby Flex Cool is a two stage crib mattress built for a standard 52 x 28 inch crib and converts to use in a toddler bed once your child moves up. A firmer core supports a newborn's spine, then a softer-feeling toddler side takes over as your child grows, so one mattress covers both stages.
Two-stage construction, a firm infant side and a plusher toddler side, is the core idea, backed by a steel coil support system and reinforced edges meant to keep the surface flat over years of use. The waterproof, PVC-free cotton cover with airflow channels is aimed at nighttime leaks and heat buildup rather than luxury feel. GREENGUARD Gold certification addresses off-gassing concerns rather than comfort.
- Dual-stage firm/toddler design
- Airflow channel cotton cover
- GREENGUARD Gold certified
- Made in the USA
Who it's for
Parents furnishing a nursery who want one mattress to carry a child from infancy through the toddler years rather than buying two separate mattresses. It fits standard full-size cribs and toddler beds at 52 x 28 inches; it will not fit mini or portable cribs.
Strengths and trade-offs
Drawn from this product's published specifications.
- One mattress covers infant and toddler stages
- Waterproof PVC-free cover for easy cleanup
- GREENGUARD Gold certified for low chemical emissions
- Steel coil core with reinforced edges
- Only fits standard 52 x 28 inch cribs and toddler beds
- Firm infant side will feel hard to an adult hand
Performance notes
The firm infant side relies on steel coils and reinforced border edges to stay flat rather than developing a dip in the center, which matters for the sleep surface behind safe-sleep guidance. Flipping to the toddler side at the right age changes the feel to something softer without changing the waterproof cover or the outer dimensions.
Specifications
| Brand | SEALY BABY |
|---|---|
| Model | EM443-STS1 |
| Dimensions & fit | |
| Item Weight | 14.9 pounds |
| Item Depth | 5.7 inches |
| Item Dimensions | 27.2 × 5.7 × 51.6 inches |
| Item Dimensions L x W x Thickness | 52 × 28 × 5.7 inches |
| Capacity & performance | |
| Age Range Description | Baby, Toddler |
| Construction & materials | |
| Material Type | Cotton |
| Construction Type | Coil |
| Cover Material | Cotton |
| Fill Material | Innerspring Coils |
| Mattress Comfort Layer Material | Cotton |
| Color | White |
| Included components | |
| Unit Count | 1 |
| Number of Packs | 1 |
| Included Components | Crib Mattress |
| Warranty & support | |
| Manufacturer Warranty Description | Limited lifetime |
| Other details | |
| Mattress Type | Standard Mattress |
| Number of Items | 1 |
| Number of Layers | 4 |
| Item Thickness | 5.7 inches |
| Product Benefits | Provides adjustable support and comfort for infants and toddlers with a dual-firmness, hypoallergenic, breathable mattress made from high-quality, waterproof materials. |
| Product Care Instructions | Hand Wash Only |
| Style Name | Flex Cool |
| Item Type Name | Bed Mattress Conventional |
| Set Name | Flex Cool |
| Additional Features | Baby crib mattresses standard, Breathable, Double Sided, Durable, GREENGUARD GOLD Certified, Hypoallergenic, Made in USA, Water Resistant |
| Shape | Rectangular |
| Item Firmness Description | Firm |
| topstyle | Tight Top |
How it compares
This product against the closest alternatives we track in cribs, beds & mattresses.
| Product | Amazon rating | Ratings | ProductDome score |
|---|---|---|---|
| Sealy Baby Flex Cool 2 Stage Crib Mattress and Toddler Bed MattressThis product | 4.7 / 5 | 3,000 | 4.6 / 5 |
| Graco Premium Foam Baby Crib & Toddler Bed MattressGraco | 4.8 / 5 | 51,203 | 4.9 / 5 |
| Dream On Me Holly 2-in-1 Mini Crib MattressDream | 4.7 / 5 | 20,518 | 4.8 / 5 |
| Delta Children Plastic Toddler BedDelta Children | 4.7 / 5 | 9,436 | 4.7 / 5 |
| Hiccapop Playard Mattress PadHiccapop | 4.7 / 5 | 24,244 | 4.6 / 5 |
Similar cribs, beds & mattresses from other brands
Questions about the SEALY BABY EM443-STS1
Common buyer questions answered straight from the product spec data - no fluff, no "it depends".
Does the Sealy Flex Cool fit a mini crib?
No. It is built for standard full-size cribs and toddler beds at 52 x 28 inches.
Which side of the Sealy Baby Flex Cool mattress goes up for a newborn?
The firmer infant side goes up first; you flip to the softer toddler side once your child moves into a toddler bed.
Is the Sealy Flex Cool crib mattress waterproof?
Yes, it has a waterproof, PVC-free cotton cover designed to protect against leaks and messes.