Fisher-Price Happy Days & Nights Diapers: * Happy Days: a perfect fit for maximum comfort and protection * Happy Nights: extra protection for nighttime, travel and longer uses * Exclusive DriNite liner on Happy Nights for extra protection * Total stretch waistband for a secure fit * SizeRight fit indicator helps you know if you need to go up or down a size * Stretchable side panels move with baby for a snug, soft fit * Available sizes: Size 3 (96 count; 76 Happy Days/20 Happy Nights) for 16-28 lbs., Size 4 (82 count; 64 Happy Days/18 Happy Nights) for 22-37 lbs., Size 5 (70 count; 54 Happy Days/16 Happy Nights) for 27+ lbs., Size 6 (60 count; 46 Happy Days/14) Happy Nights) for 35+ lbs.