Loulou Lollipop Adventure Begins Lightweight 1 TOG Sleep Sack for babies 3-12 Months. Keep baby safe and comfortable all night with our handy muslin sleep sack. Designed specifically for bedtime and naptime, this cozy and clever solution can’t be kicked off—which means a more restful sleep for baby. Made with soft, breathable fabric, it features a sleeveless design that’s perfect for late spring and summer months.