A knife having a body and a slide member slideable in the body. The slide member engages a blade assembly that is arranged to move with the slide member. The slide member is movable to position the blade assembly at a position of use and a release position wherein the blade assembly can be released from the slide member. The slide member is movable to retract the blade assembly into the knife body. The knife also includes an actuator member that can be actuated to move the slide member to a disengaged configuration wherein the blade assembly can be disengaged from the slide member to permit the release therefrom. The positioning of the blade assembly at the release position and subsequent movement of the slide member to the disengaged configuration by actuation of the actuator member releases the blade assembly from the slide member.