LAYEN CSB - Home Security/Child Security Audio Surveillance. SIM Activated with Crystal Clear Sound &ndash; Call to listen and check everything is OK The LAYEN CSB is the perfect home audio surveillance device. It's tiny and unobtrusive making it easy to conceal. Despite its' small size, it's a high quality security device, providing clear sound quality, long standby duration (around 2 days) and 1-2 hours constant use (extendable with a portable power-bank). It works through a Mobile GSM SIM card (not supplied). Simply insert a PAYG / PrePay SIM into the device and call it to turn the device on, you will be able to hear what is happening in the surrounding area straight away. Ideal Home Security Device. You can conceal the CSB easily within your house so any potential thieves wouldnt know it was there. Set to voice activation and if the device hears anything it will call you. I.e. if somebody broke in and made noise, the device would pick this up and call you. ** IMPORTANT PLEASE READ ** The LAYEN CSB requires a GSM network (not CDMA) and runs off four GSM frequencies: 850/900/1800/1900 MHz. It works exactly like a mobile (with service / network reception etc. It will not work if the SIM card requires an IMEI number to activate it, as the CSB does NOT have an IMEI number to enable this) Need to check up on your children? - Check that your children are sleeping soundly! You can also use to check up on your pets if youre away all day / worried about them - Versatile device - you can either call to listen OR you can set it to Voice Activation: when there is a sound above 45db within 10 metres of the device, you will be called to listen.