The product is mainly used in the frozen or cold environment.To obtain good vision in the rain, snow, ice or dust environment, the window wiper and clear view screen are necessary equipment for ship. And installation of them for marine ships is mandatory requirement of classification society. There are two types of this product. One is with the internal motor, and the other one is with the external motor. This window wiper is enclosed with heater on its shell guide to guarantee the smooth scrape in freezing weather. If you don’t need the heater, you can also choose the product without the heater. If you have any questions, you can contact us, we will give you the detailed answers.Wiping distance,case length, blade length and arm length can be customized as required.