Viper Laser Throw/Toe Line Marker State-of-the-art laser beam which accurately marks your throw/toe line; Provides a modern alternative to traditional adhesive floor markers Compatible with both steel and soft tip darts, making the Viper laser throw/toe line marker an essential accessory for causal and competitive dart player alike Bright and energy efficient lighting of the laser allows it to be seen even in intense daylight; Can be positioned at any vertical angle near your dartboard After mounting the laser on a cabinet or wall, tighten the 2 screws on each side of the laser to ensure it stays in place even if it is bumped Requires 4 AA batteries to operate (sold separately) giving you a clutter-free room with a cordless design; All mounting hardware is included