Materials: Zinc alloy, steel, ABS resin Product size: 3.5cm x 1.2cm x 4.2cm You can change the PIN to your preferred number. Please make a note of the PIN and be careful not to forget it. Do not use outdoors. This product is not a perfect security measure. Please use it as a simple security device. There are no noticeable stains, but Please understand that this is a personal inspection and home storage. If you can understand this, please purchase. Also, please use it before points expire or coupons expire!