LemonBest Waterproof Night Fishing Flash LED Light Smart Sensor Rod Tip Strike Alert, Pack of 3 Energy save system gives battery extra long life Visible up to 100m ; Waterproof design; Intelligent motion sensor Automatically turns on when attached to rod tip Supplied with two attachment clips 3mm and 5mm so it will fit on the tip of most rods. Smart processor detects a bite compared to other rod and line movement, such as wind or various and movements.