Macbook 12 Sleeve - Bear Motion Premium Felt Sleeve Case for Apple MacBook 12 with Retina Designed and made for Macbook 12 (might NOT fit other macbook models) Great for organizing your potable electronics on the go. Made for Macbook 12 - A1237, A1304, A1369 or A1466 A piece of leather string is tied to one button. You use it to fasten the front cover by tying the other end of the string to the other button. If you are tired of the leather string after a while, you can always change it to any yarn or flex fiber string that you can get in any craft store.