Northern Tool offers the Strongway 36" Air Curtain for $159.99. Coupon code "253361" cuts the price to $139.99. Opt for in-store pickup to avoid the $22.49 shipping charge. That's $30 off list and the lowest price we could find. Commonly used for customer entrances, drive-up windows, and concession stands, it regulates air flow at thresholds and deters flying insects. Deal ends July 4.