We love this cushy, foam sit-up seat, which lets babies sit upright sooner! It offers greater security and peace of mind than others, because it 1) straps to chairs and 2) has a three-point harness (instead of simply a passive support). Plus, to "boost" the value, we're including a snack tray, wipe-clean placemat, and snap-on toy. For ages 3-12 months. Bring along in our top-rated Booster Seat Tote (sold separately). A One Step Ahead Exclusive!. Once your baby can keep his head up, he can sit comfortably upright in this sit-up seat . Booster seat is soft and comfortable; it's made of non-toxic polyethylene foam . Lightweight and portable. Use at home, while visiting, and more. . Can be used on any flat surface, including chairs and floors . 15¾"L x 14¼"W x 9½"H. Seat measures 7"L x 7"W x 8"H. Leg opening is 2½" in diameter. Seat strap measures 14"L each; back straps measure 15"L each.