The iBR9000 iButton reader is small, but tough. It has a stainless steel read head and a fiberglass-reinforced nylon case. While it is small enough to fit in a pocket, on a key chain, or on a lanyard, it can store more than 9000 iButton IDs with date and time. This makes it ideal for applications such as guard tours and maintenance checks. The replaceable CR2 lithium battery provides long life and is readily available.