The Seashell Sensor is an item available in the Switch remake of Link's Awakening. It can be obtained at the Seashell Mansion after collecting 15 of the 50 Secret Seashells. The sensor will automatically play a sound when Link reaches a portion of a map where a Secret Seashell is located. This makes hunting for the remaining shells and obtaining the Koholint Sword much easier. It can be turned on and off in the menu.