Electrical life:50000Primary Characteristic:It is stepless speed regulation of cross current switch, which have self-lock and positive and negative rotate device.
电器寿命：50000主要特征：交流无级调速开关，带自锁和正反转。
2
Electrical life: 50000primary Characteristic: it is stepless speed regulation of cross current switch, which have self-lock and positive and negative device.
电器寿命：50000主要特征：交流无级调速开关，具自锁和正反装置。
3
The side of the safety door is provided with the magnetic self-locking device which consists of a lock box and a small magnet.