Wireless electronic key finder, find keys by card. 1. RF technology 2. long distance:40m 3. Small size 4. long battery life RF Electronic key finderIntroduction:Put the card in the wallet, and the receiver with keys , when you can't find it, just push a button on the card, and the receiver will sound alarm and LED flickering.(it can find the lost thing in a 400 square meter house)The alarm will ...