NAPA Wiper Blade (NWH24) Generally speaking, wipers are designed to last between 6 months and a year. There are, however, factors that impact your wiper's lifespan. This can include things like tree sap, extreme summer and winter conditions, fuel particles as well as the quality of the blade itself. As they are a safety-critical element of any vehicle, they should be replaced as soon as their performance starts to diminish. All wiper blades from NAPA are designed and manufactured to OE specifications. This is followed by testing to OE specification. If the product does not perform or meet the OE criteria, it will not get released into mass production until it matches or exceeds the OE characteristics. All products are produced in a fully certified production facility. The plant is certified to automotive and quality standards ISO9001 and TS16949, as well as the environmental standard ISO14001.