A connector according to the invention includes: a metal cylinder; a conductive receptacle having an end fitted in an end of the metal cylinder; a pin assembly fitted in the conductive receptacle; pins fixed to the pin assembly, the pins being connected to a cable; a circuit board fixed to the other end of the metal cylinder, the circuit board having through holes electrically connected to the pins; and a sealant disposed between the circuit board and the pin assembly, the sealant infilling gaps between the pins and the through holes of the circuit board.