This fabulous upgraded offer includes 4 total sets at our introductory price of just $9.99 per set, so you'll get 16 total to secure and protect your home with confidence. As an added bonus, you'll also receive a $20 value gift free, it's the wireless and portable motion sensor light, just place it anywhere, and the battery operated safety light to turns on automatically when any motion is detected. It's great for dark closets, dark stairs, or anywhere that you want the light to come on automatically. And it turns itself off automatically after a few minutes. This $20 value is free plus $3.99 shipping which is already added to your shipping and handling cost when you place your order. And if you're not 100% satisfied, return it for within 30 days for a full merchandise refund, but keep the motion sensor light as our gift, just for selecting this upgraded system today. Your total for the 4 sets is $39.96 plus $10.98 shipping and handling.