PRICES MAY VARY. Attention: For the 809 series, the buttons are decorative, NOT funtional. the middle knot is just decorative, you can make knot via the separate tie.(The tie is separated in the package.),But for the 572 series,the buttons are funtional,the middle knot is self-tie. Material: Polyester. Soft material, light and comfortable, a must-have dress in your wardrobe. Occasion: This Spaghetti Strap dress is great for daily wearing, office, party, beach, cocktail,wedding, club, dating, eve