These stamped aluminum key chips allow for easy identification of Postal keys with it's "USPS" imprint. These durable chips can also be used in an exchange system for arrow keys--Letter Carriers simply trade a chip with his or her name for an arrow key. It is known at all times where the key is and who has it. These efficient key chips feature a durable aluminum construction, an imprint for easy identification and are sold in boxes of 100. Custom imprint and numbering available call for pricing (MIN 50 boxes of 100).