This headphone jack cover will screw shut and seal the headphone jack if using the CTX 3030 underwater

4 “AA” Batteries Included – Power your ACE 400 right out of the box

stable connection between the upper and lower shaft sections

detailed audio response

Nokta Waterproof 4-AA External Battery Pod for Simplex Wireless Metal Detector This headphone jack cover willKeep detecting longer with the genuine Nokta waterproof external battery pod for compatible Simplex metal detectors. The pod uses four readily available AA batteries, making it a practical backup power option in the field. Features Uses four AA batteries for convenient backup power Waterproof design for compatible Simplex setups Ideal for travel, extended hunts, and emergency power Genuine Nokta accessory Compatibility For compatible Nokta Simplex