The P17R Core is an extremely reliable and bright flashlight. The P17R Core is an extremely reliable and bright flashlight. It is ergonomically-friendly and can be easily operated with the Fast Action Switch. The patented Advanced Focus System provides a continuous transition from a broad flood beam to a sharply focused long-distance beam. The energy for this extremely durable flashlight is provided by a rechargeable Safety Ytrion Cell, one of the safest and most durable rechargeable battery cells in the world.