... for the observation of the test products during the testing process. the window is equipped with sweat-proof electrical ... , failure warning system AccessoriesRecorder (optional), watching window, 50mm testing hole, PL internal bulbs,partition plate, dry and wet ball ... 50/60Hz Welcome to contact us! Candice FanDongguan Zhongzhi Testing Instruments Co.,Ltd.Tel:86-769-88808158/85998260Fax:86-769-88808258 ...