... , no impurities, anti-leakage, do not melt under high temperature, in line with the requirements of environmental protection. 2. Metal frame body ... using built-in fuse protection device, safe and reliable. Shutter fan (all plastic) 1. The latest Blade design, more in line with the principles ... . 3. Super quiet, beautiful and generous. 4. Motor using built-in fuse protection device, safe and reliable.