The Schertler Basik is an electrostatic stick on pickup made by a Swiss company, who specializes in making pickups and amplification for acoustic instruments.
The Basik is as the name implies Schertlers most basic and cheapest pickup system.
There are three versions of Schertler Basik - the Basik Set, the Basik pro and the Basik Road.
The Set comes with a battery box and a non invasive putty for the application of the pickup to the instrument (this is the tested version).
The Pro adds a 48v adaptor for phantom powering.
The Road provides both the battery box and 48v adaptor.