Kirby Holmes and Evan Daugherty of pet air pollution mask company K9 Mask say they were selling stylish air filter masks for people when they realized some customers were finding them by searching for 'air filter mask for dogs.' Between wildfires and the pandemic, masks are suddenly everywhere. The company has sales, but the Sharks are worried sales aren't higher, because this might be a once-in-a-lifetime moment for mask sales. From season 12, episode 6 of 'Shark Tank.' Watch 'Shark Tank' FRIDAY 8|7c on ABC, streaming, on demand, and Hulu.