An electrical connector , comprising: a housing having a front end, a back end, a top side, a bottom side and a cavity between the top side and the bottom side, wherein the housing is configured to be mounted to a substrate at the bottom side, wherein the cavity is to receive a circuit board therein and the housing comprises a plurality of parallel grooves, comprising contact grooves formed on the top side and a pair of fixing grooves formed on the bottom side; a plurality of contact elements attached to the housing, each contact element having an upper contact arm disposed at the top side and positioned in a respective contact groove of the plurality of contact grooves, and a lower contact arm disposed at the bottom side; a pair of locking members attached to the housing, each locking member having a lock arm positioned in a respective fixing groove of the pair of fixing grooves along a direction from the back end to the front end of the housing , wherein the upper contact arm and the lower contact arm of each contact element and the lock arm of each locking member being resiliently deflectable away from the cavity to allow insertion of the circuit board into the cavity, wherein the upper contact arm and the lower contact arm are configured to be in electrical contact with the circuit board when said circuit board is inserted into the cavity, and the lock arm is configured to spring back to engage and lock the circuit board to the housing, and wherein the contact elements and locking members each comprise a tail extending from the housing to form an array of parallel tails at the back end of the housing. a housing having a front end, a back end, a top side, a bottom side and a cavity between the top side and the bottom side, wherein the housing is configured to be mounted to a substrate at the bottom side, wherein the cavity is to receive a circuit board therein and the housing comprises a plurality of parallel grooves, comprising contact grooves formed on the top side and a pair of fixing grooves formed on the bottom side; a plurality of contact elements attached to the housing, each contact element having an upper contact arm disposed at the top side and positioned in a respective contact groove of the plurality of contact grooves, and a lower contact arm disposed at the bottom side; a pair of locking members attached to the housing, each locking member having a lock arm positioned in a respective fixing groove of the pair of fixing grooves along a direction from the back end to the front end of the housing , wherein the upper contact arm and the lower contact arm of each contact element and the lock arm of each locking member being resiliently deflectable away from the cavity to allow insertion of the circuit board into the cavity, wherein the upper contact arm and the lower contact arm are configured to be in electrical contact with the circuit board when said circuit board is inserted into the cavity, and the lock arm is configured to spring back to engage and lock the circuit board to the housing, and wherein the contact elements and locking members each comprise a tail extending from the housing to form an array of parallel tails at the back end of the housing. <EOS>