. Need a backpack without the bulk? Jump for joy, because the Jumping Jack backpack gives you a packable bag with drawstring straps. Perfect for a quick trip to the gym or a day at the theme park, Jumping Jack is light and simple, with plenty of pockets inside and out.. Dimensions: 15"W x 18"H x 5"D Weight: 0.65 lb Shoulder Strap Drop: 12" to 18" Top Handle Drop:2" NWT