This device uses a sensor to detect the tilt of the fishing rod during night surf fishing, alerting you to a hit with sound and light! Essential for surf fishing! Features: * Loud alarm volume * LED lamp (white) flashing - do not look directly at it ⚠️ The body is made of break-resistant ABS resin, making it resistant to impacts such as drops. This depends on the conditions of use. The sensor is IPX4 water-resistant, so you don't have to worry as much about water getting in on rainy days and the sound not working, but you can also put it in a plastic bag, etc. ⚠️ IPX4 water resistance: Safe to touch with wet hands, and withstands some rain or splashes. Many products, such as mobile phones, digital cameras, and emergency radios, fall into this category, and it's the minimum level needed for kitchens and outdoor use. Protected against harmful effects from water spray from any direction. Tested with 10 liters/minute of water sprayed from all directions from a height of 300-500mm for 10 minutes. Splash-proof. Not sold in fishing tackle stores. Easy to attach and detach with a clip. This clip securely holds the rod and has rubber to prevent scratches. The sound and light are designed to be heard and seen even in the sea breeze, but because it is handmade, there may be slight variations in the sound and light. Please understand. Uses two AAA batteries. Economical. How to use: Pull out the sensor's pull-out pin, and the alarm and LED lamp will flash and sound when tilted (on). Push the pin in to turn it off. Caution ⚠️ The pull-out pin does not come out completely. It remains attached to the main unit. Although the screws are stainless steel, apply lubricant (such as silicone oil) to the bell, spring, and pull-out pin after fishing to prevent rust. Photos 4-5 are for reference. The sensitivity of the sensor can be adjusted by angle, so adjust it each time you use it.