picture of the measurement location - Use up to six smart probes at the same time - Wireless range of appr. 15m (depends on mobile device used) Preconditions for using: - Use a testo Smart Probe (testo 405i, 410i, 605i, 510i, 115i, 549i, 805i, 905i), a testo 552 or a testo 770-3 - Requires iOS 8.3 or newer, plus mobiles end device with Bluetooth 4.0