NOTE: Size 4 = 2T-3T; Size 5 = 3T-4T; Size 6 = 4T-5T The expiration date is for REWARDS not for the product. Get outstanding leak protection while potty training! You and your little boy will know when he’s ready for potty training. That’s why Pampers Easy Ups Training Pants are designed for when he’s ready for potty training during the day but still needs protection at night. Plus, they feature Pampers Leak Protection for fewer leaks than the other leading training pant.* And they feature fun Thomas the Tank Engine designs. *Based on size 4.