The Movo F33 windscreens are designed to reduce unwanted vocal pops and broadband wind noise with minimal high frequency loss. these windscreens are effective in minimizing wind noise and plosive sounds. They are most effective in calm to light breeze conditions (0-7mph), and can be used indoors for protection against drafts caused by air-conditioners. Users can generally expect a notable reduction in wind noise, with very slight dampening of high frequencies. For most applications, this is a worthwhile exchange.