An audible end cap , comprising: a waterproof loudspeaker , for generating multiple alarm sound combinations, wherein the diameter of the waterproof loudspeaker is greater than 2cm; a back cover provided with a first connecting portion whereby the back cover is configured for being fixedly installed on a metal detector, wherein the waterproof loudspeaker is installed in the back cover ; an audio connector electrically connected to the waterproof loudspeaker , wherein the waterproof loudspeaker is capable of receiving and emitting the sound signal output by the metal detector through the electrical connection between the metal detector and the audio connector ; wherein the audible end cap further comprises a protective collar , a first protective bracket , and a second protective bracket , wherein the waterproof loudspeaker is fixedly clamped between the first protective bracket and the second protective bracket , wherein the protective collar is fixedly installed in the back cover and is sleeved and fixed on the outer periphery of the first protective bracket and the second protective bracket , and wherein the first protective bracket , the second protective bracket and the waterproof loudspeaker are all contained in the back cover ; and wherein the protective collar is provided with a snapping groove , the first protective bracket comprising a first snapping ring plate , and the second protective bracket comprising a second snapping ring plate , wherein the first snapping ring plate and the second snapping ring plate abut against each other and are fixedly engaged in the snapping groove . a waterproof loudspeaker , for generating multiple alarm sound combinations, wherein the diameter of the waterproof loudspeaker is greater than 2cm; a back cover provided with a first connecting portion whereby the back cover is configured for being fixedly installed on a metal detector, wherein the waterproof loudspeaker is installed in the back cover ; an audio connector electrically connected to the waterproof loudspeaker , wherein the waterproof loudspeaker is capable of receiving and emitting the sound signal output by the metal detector through the electrical connection between the metal detector and the audio connector ; wherein the audible end cap further comprises a protective collar , a first protective bracket , and a second protective bracket , wherein the waterproof loudspeaker is fixedly clamped between the first protective bracket and the second protective bracket , wherein the protective collar is fixedly installed in the back cover and is sleeved and fixed on the outer periphery of the first protective bracket and the second protective bracket , and wherein the first protective bracket , the second protective bracket and the waterproof loudspeaker are all contained in the back cover ; and wherein the protective collar is provided with a snapping groove , the first protective bracket comprising a first snapping ring plate , and the second protective bracket comprising a second snapping ring plate , wherein the first snapping ring plate and the second snapping ring plate abut against each other and are fixedly engaged in the snapping groove . <EOS>