[NEW 2018] Effective Ultrasonic Mosquito Repellent (2-Pack) - Odorless Non-Toxic Portable Pest Control Repeller Anti Insects, Bugs, Roaches w/ Dragonfly Mode - For Indoor and Outdoor (White 2-Pack) Using the high carbon steel material, having a strong penetrating power. Easily to staple, saving of time and labour. The needle of the nail is sharp, with good stability. Nail is not easy to break, convenient to use and transport. Material: Carbon Steel