I LOVE these. I purchased four from Joann.com last year. I use them for my Viking bobbins, and I used the one empty one for my extra presser feet! It is the perfect size and shape for presser feet, and small enough to be conveniently stored near the machine! LOVE these and intend to order more!
I use many different threads and have 4 sewing machines. This box is economical enough that I can have a bobbin box for each type of thread and, in some cases, devoted to one machine. And it holds 30 bobbins. I'm about to purchase 5 more.