? Features Environmental product， no radiation RF wireless technology 1 transmitter matches 1 receiver Super electronic key finder Stable function， anti lost function Long battery last time and working distance The receiver is small and light， very easy to secure the keys or other things The transmitter is designed as a bank card size， easy to put in into the wallet Find lost keys just by a button General Specs Type Key Finder  Transmitter weight 15 g Transmitter size (L x W x H) 8.4 x 5.5 x 0.4 cm Receiver weight 13 g Receiver size (L x W x H) 4.5 x 2.8 x 1.1 cm Package Details Weight: 63.13 g Size: 20.5*14.3*2.5 cm