The ZN12-T-2WP is a T-shaped dendrometer with two sensors to be mounted on tree stems >7 cm in diameter. The two sensors allow measuring stem radius changes over bark and on xylem in parallel. The frame is made out of one piece of carbon fibre (CFK) and is consequently combined with stainless steel elements (rods and nuts). The two electronic displacement-sensors (linear motion potentiometer) are weather-proof but not sealed and are applicable under most conditions. The WP sensors are not recommended for very wet conditions.