The 2500 Series portable receiver is a small receiver that is compatible with any of our 2500 Series transmitters. The first thing you notice about the portable receiver is its small size. The receiver is only 2.5" x 1.25" x .75". The other thing you will notice is the LCD display. The rechargeable Li-Ion battery will hold a charge for up to 10 days. In addition, the portable receiver will also give an audible tone for each of the four zones and a vibrate alert for times when you need it to be silent. It is capable of receiving and storing alert signals from up to 4 zones. Each zone can store up to 400 events with a date/time stamp. In addition, each zone can store up to 999 events without the date/time stamp. With the counter function you will know when the monitor was activated.