Start your wireless measurements on refrigeration and air conditioning systems as well as heat pumps immediately. The practical set with the digital technician's aid testo 558s, featuring Bluetooth connectivity to the wireless temperature and vacuum probes, along with the included 4-piece charging hose set, provides the ideal foundation for everyday measurement tasks. The testo 558s allows for intuitive operation thanks to its touchscreen and clear measurement graphics on a large color display. In addition to the touchscreen, the technician's aid can also be operated with buttons for use while wearing gloves. With A3 and A2L compatibility, high robustness with IP 54 rating, and a hybrid charging system using both rechargeable batteries and standard batteries, the technician's aid is optimally suited for any situation.