Simple bracelet that holds 1/4 inch by 1/16 inch magnets (with a slot to insert them). Great for pins, needles, and other easy-to-lose things (keys?).
Sizing should fit many wrists of about 20cm in circumference (may vary depending on proportions).
The magnets aren't included, but you can get 20-50 of them for very cheap on Amazon (I found them for $6).
Get the magnets on Amazon