4 Season Ultimate Baby Sleep Bag

by Woolino

4 Season Ultimate Baby Sleep Bag

by Woolino

$129.99 – $149.99


The award-winning 4 Season™ Ultimate Baby Sleep Bag by Woolino keeps your baby at a perfect temperature throughout the night, year-round. That means there’s no need to worry about which weight sleeping sack to use, or whether your baby will be too hot or cold while sleeping – they’ll always be just right!

Made with super-fine and supremely breathable merino wool, it helps keep your baby warm when it’s cold and cool when it’s warm. That temperature regulation means that your baby will sleep comfortably throughout the night– and that means a better night’s sleep for you too. It comes in a universal size that fits babies from 2 months to 2 years or kids from 2 to 4 years! It saves you buying a different sleeping bag for different seasons, as well as buying larger ones as they grow.


  • 100% natural silky-soft hypoallergenic merino wool lining and the finest organic cotton outer.
  • Can be used year-round! Suitable for room temperature 63-75F (17-24C). Because of merino’s unique ability to regulate body temperature, it helps keep your baby warm when it's cold and cool when it's hot.
  • It has a universal size so it can be used for babies 2 months up to 2 years old. For smaller babies, simply close the underarm snaps to adjust the fit.
  • You don’t have to buy a different sleep bag every few months. Woolino Ultimate 4-Season Sleep Bag is the only baby sleep bag your baby needs, in winter or summer, until they turn two years old.
  • It features double shoulder snaps and a two-way side zipper, so it opens up completely flat for easy dressing without waking the baby. 
  • For easy nighttime diaper changes, you can open the bottom only. Zipper-pull guards protect baby's skin and discourage baby from chewing on the zipper pull.
  • A closable seatbelt opening allows for easy transfer between stroller, car seat, and crib, so you can keep your baby’s sleep routine intact while on the go.
  • A safer alternative to loose blankets - helps your baby stay covered through the night, replaces loose blankets in the crib, and promotes back sleeping.
  • Free Nursery Thermometer with a dressing guide included.


  • 2 - 24 Months Size: Suitable from 10 - 32 lbs and 23-35" tall
  • 2 - 4 Years Size: Suitable from 25-42 lbs and 34-42" tall
  • We do not recommend sizing up. The sleep bag should be well-fitted around your child's upper body for a safe and secure fit. We suggest using our recommended sizing guidelines to find the correct size based on your child's age, height, and weight.
  • Lining Fabric: 100% natural silky-soft hypoallergenic merino wool
  • Outer Fabric: Organic cotton

Care Instructions:

  • Machine wash on Low, 100°F /40°C max. Close zipper
  • Use wool approved or mild detergent
  • Do not soak or bleach. Avoid fabric conditioners and softeners
  • Hand wash: Gently soak and squish in lukewarm water. Do not agitate, wring, or rub wool against wool
  • Tumble dry on “No Heat” setting. Dry flat when possible
  • Merino wool by nature is self-cleaning and does NOT need to be washed as frequently as other fabrics. To refresh and reduce washing, air the garment often.

Additional Information:

  • What is the TOG rating? Are they winter or summer weight?
    • Woolino 4 Season baby sleeping bags are designed to be worn year-round. They are made from 100% natural breathable fibres and contain NO synthetic filling. Therefore, they do not have a fixed TOG. The fine merino wool lining helps naturally in regulating baby’s body temperature, keeping baby warm in winter and cool in summer.
    • Woolino sleep bags are recommended to be used in room temperatures 63-77F (17-25C). Simply adjust the layers of sleepwear worn under the sleeping bag to suit the nursery temperature. You can find our suggested dressing guidelines on the back of the room thermometer that comes with every baby sleep bag.
  • What is the difference between Woolino Ultimate (universal size) and Woolino Basic Baby Sleep Bags?
    • Both collections have the same weight fabrics, merino wool lining and organic cotton outer. The differences are:
    • Woolino 4 Season Ultimate Baby Sleep Bag has universal sizing: 2 months - 2 years, underarm snaps for adjusting the size of the armholes, travel slots for use in car seats, strollers, bouncers etc., & both shoulder snaps.
    • Woolino 4 Season Basic Sleep Bag has a simpler design: no snaps and no travel slots; it comes in traditional sizes: 0-6, 6-18, 18-36 months.

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