Woolino 4 Season Ultimate Sleep Bag
Sleeveless year-round sack with a merino lining and organic cotton shell, sold in baby and toddler sizes (per the maker).
- $109List price
- 2Sizes
How the 4 Season Ultimate Sleep Bag stacks up
Against the 39 sleep sacks we track. The shaded band is where the middle half of them fall; the dot is this one.
Above the typical range for sleep sacks ($34.99 to $58).
What sets the 4 Season Ultimate Sleep Bag apart
Measured against the 39 sleep sacks we compare, from each maker's published specs.
- Highest list priceof the 31 sleep sacks that list it: $109
Next to its closest matches
- Woolino 4 Season Footed Sleep BagNext to it, the 4 Season Ultimate Sleep Bag is $16 more.
- Woolino 4 Season Classic Baby Sleep BagNext to it, the 4 Season Ultimate Sleep Bag is $30 more.
- Kyte Baby Slumber BagNext to it, the 4 Season Ultimate Sleep Bag is $34 more.
Size chart
| Size | Weight | Age |
|---|---|---|
| Baby | from 10 lb | 2–24 months |
| Toddler | – | 24–48 months |
As Woolino publishes it.
Listed features
- Wool lining suits a wide range of room temperatures
- Underarm snaps adjust fit for smaller babies
- Seatbelt opening for car seats
Worth checking
- List price $109
- No fixed TOG, so layering has to be adjusted by the parent
Where to buy the 4 Season Ultimate Sleep Bag
Prices and availability change. We may earn a commission from some links.
- Check for recalls: Search the agency's recall list with the model number and date code from the label: CPSC recall search.
- Swaddling and safe sleep: see the AAP's swaddling page and guide to safe sleep. Check the label and the maker's instructions, and ask your pediatrician about your child.
Full specs
| Woolino 4 Season Ultimate Sleep Bag | |
|---|---|
| Type | Sleep sack |
| List price | $109 |
| Sizes | Baby: from 10 lb, 2–24 months Toddler: 24–48 months |
| Arms | Arms out |
| Closure | 2-way side zipper with shoulder snaps and underarm snaps (baby size) |
| Material | Merino wool lining, GOTS organic cotton outer |
| Organic | Yes, per the maker |
| Machine washable | Yes |
| Maker's use notes | Use in rooms 63-75F; minimum 10 lb; do not size up; fit snugly around upper body |
Compare the 4 Season Ultimate Sleep Bag with
How each closest rival differs from the 4 Season Ultimate Sleep Bag, from the makers' specs.
- Woolino4 Season Footed Sleep Bag$93$93
- $16 less
- Woolino4 Season Classic Baby Sleep Bag$79$79
- $30 less
- Kyte BabySlumber Bag1 TOG$75$75
- $34 less
- Kickee PantsFluffle Sleep Bag1.6 TOG$60$60
- $49 less
4 Season Ultimate Sleep Bag: questions answered
From Woolino's published specs, last checked 2026-11-02.
What sizes does the Woolino 4 Season Ultimate Sleep Bag come in?
Per the maker: Baby (10 lb and up, 2 to 24 months); Toddler (24 to 48 months). Check the maker's size chart.
What's the difference between the Woolino 4 Season Ultimate Sleep Bag and the Woolino 4 Season Footed Sleep Bag?
By the maker specs, the 4 Season Footed Sleep Bag lists for $16 less. See them side by side.
Still wondering? Write to us at hello@cribpicks.com and we'll look it up.
More sleep sacks
- Kyte BabySleep Bag0.5 TOG$58$58
- aden + anaisOrganic Cotton Light Sleep Sack (1.0 TOG)1 TOG$49$49.99
- aden + anaisBoutique Muslin Light Sleep Sack (1.0 TOG)1 TOG$49$49.99
- Love to DreamLong Sleeve Sleep Bag1 TOG$49$49.95
- Little UnicornCotton Muslin Sleep Bag1.1 TOG$49$49.99
- ergoPouchSleeved Sleep Sack (2.5 TOG)2.5 TOG$69$69.95
Where these specs come from
Last checked 2026-11-02. Spot something wrong? Tell us. Read our editorial and safety policy and corrections.