... the thin card in the wallet, tie the keychain with the keys, when you want to find ... , just push the button on the card,the keychain will beep if it is within the working distance ... 2. Size for Card: 84X55X3.8mm; 3. Size for keychain: 44X28X10mm 4. Beep sound: 75 DB; 5. Frequency: ... 3V; Card size Card logo can be printed in colorful. Keychain Color: red, blue, pink, grey, yellow, and customzied ...