The EnerG+ EN656 Solar Pest Repeller Stake with Rechargable Batteries - Set of 2 makes sure your yard is safe and free of unwanted critters. Two repeller units are included in this set, letting you cover a wider area. The units are made from weatherproof ABS plastic and feature solar panels that charge all day and continue to work overnight. Every minute, the units emit a combination of sound and vibration that scares away prey animals and some smaller predators without causing them harm. This set covers a 6,000 square foot area.