This is an optional external antenna for Visonic GSM modules. The GSM antenna improves cellular transmission and reception.Visonic External Antenna for GSM Modules£28.93PriceQuantity*Add to CartBuy NowMore Info.How it works: Mount antenna on the the desired site surface, connect its connector to the internal GSM module. Works with all Visonic GSM/GPRS modules. Cable length: 10 Feet
