This is an extension bra hook that allows you to adjust the underbust size of your bra. It stretches, so it's comfortable even when you move. This is a convenient item that allows you to adjust the size when your weight or body shape changes. It's economical because you can continue to use your bras even if your size changes. Please use it as an underbust hook or underbust clasp. Quantity: Set of 4 Size: Approximately 10cm wide, 7.5cm high Distance between the centers of the hooks: Approximately 1.9cm Colors: White, Red, Black, Skin Tone Pink, Gray, and Blue are also available. Please comment if you would like these colors. You can choose any 4 colors from the photos. Please let me know your color choices before purchasing. If you don't specify, I will ship white, black, red, and skin tone. (I will ship the 4 pieces in the first photo.) No discounts, sorry. ••✼••┈┈••✼✼••┈┈••✼•• This elastic type is available in 3-row, 4-row, 5-row, and 6-row options. Please comment if you would like these. I plan to ship via Yu-Yu Mercari anonymous shipping. Thank you.