Gas soldering iron, single device, with cap and locking device. For demanding soldering tasks without cumbersome cables, wherever a power supply is not possible, e.g. in the installation, service and repair sector. Thanks to various interchangeable attachments, also suitable for heat shrink work, micro welding and for cutting plastic films and sheets. With electronic ignition, continuously adjustable power, temperatures with open flame up to 1,300°C, soldering up to 500°C, heat shrinking up to 500°C, burning time approx. 60 min.