SwaddleDesigns Transitional Swaddle Sack, Arms Up Half-Length Sleeves & Mitten Cuffs, Swaddle for Newborn Transition to Baby Sleep Sack Wearable Blanket, Med, 3-6 Month, 14-21 lb, Blue Tiny Triangles

Little sleeves with big purpose. When mitten cuffs on the 1/2-length sleeves are closed, The sleeves provide partial suppression of the startle reflex, and if baby rolls to tummy, baby can use arms to lift torso and reposition head. Better, safer sleep.
LITTLE SLEEVES with BIG PURPOSE. Arms Up Swaddle with 1/2-length sleeves and mitten cuffs closed provide partial suppression of Startle Reflex to help baby SLEEP BETTER; if baby rolls onto tummy, baby can push up to access air for SAFER SLEEP
EASIEST way to move from a traditional swaddle to a wearable blanket. Transitional Swaddle Sack is not a tight swaddle nor a loose sack. Snug fitting and Hip Healthy design supports baby in natural position and flexed position to help baby feel secure
FOLDOVER MITTEN CUFFS MAY BE WORN OPEN OR CLOSED; Caregiver can open one or both cuffs, so baby can SELF-SOOTHE, or close the cuffs to PROTECT BABY FROM FACIAL SCRATCHES and provide partial suppression of startle reflex.
100% Cotton. TOG 0.7 Soft stretchy cotton knit. 2-way zipper for easy diaper changes. Use baby weight to select size: Small 6-14 lbs 0-3 Mo; Medium 14-21 lbs 3-6 Mo; Large 21-24 lbs 6-9 Mo. Machine wash. Tumble dry. US Patent 11,812,795 WW patents online