A packaging unit comprising: a container adapted to hold contents to be dispensed and having an aperture at an end thereof, the aperture being sized to dispense the contents therethrough; and a lid configured to slideably engage the container about the end thereof, the lid being slideable in a first direction between a closed position in which the lid covers the aperture and an open position in which the aperture is at least partially uncovered, wherein the container includes at least one resilient portion (1304, 1307) capable of being deflected in a direction substantially perpendicular to the first direction so as to disengage the lid from the container when in the closed position such that the lid is capable of sliding in the first direction to the open position; wherein the lid comprises a top wall and a side wall extending from the top wall, the side wall defining a lid aperture, and the container further comprising a flexible arm having the at least one resilient portion, the flexible arm further having an enlarged portion configured to be received within the lid aperture when the lid is in the closed position, the at least one resilient portion of the arm being configured such that the enlarged portion is capable of being deflected out of the lid aperture to permit movement of the lid in the first direction; characterized in that the packaging unit further comprises a lip extending from the side wall of the lid; and the container includes a front portion which prevents excessive motion of lid in a direction opposite to the first direction once the aperture is substantially covered, the front portion defining a groove configured to receive the lip when the lid is in the closed position. a container adapted to hold contents to be dispensed and having an aperture at an end thereof, the aperture being sized to dispense the contents therethrough; and a lid configured to slideably engage the container about the end thereof, the lid being slideable in a first direction between a closed position in which the lid covers the aperture and an open position in which the aperture is at least partially uncovered, wherein the container includes at least one resilient portion (1304, 1307) capable of being deflected in a direction substantially perpendicular to the first direction so as to disengage the lid from the container when in the closed position such that the lid is capable of sliding in the first direction to the open position; wherein the lid comprises a top wall and a side wall extending from the top wall, the side wall defining a lid aperture, and the container further comprising a flexible arm having the at least one resilient portion, the flexible arm further having an enlarged portion configured to be received within the lid aperture when the lid is in the closed position, the at least one resilient portion of the arm being configured such that the enlarged portion is capable of being deflected out of the lid aperture to permit movement of the lid in the first direction; characterized in that the packaging unit further comprises a lip extending from the side wall of the lid; and the container includes a front portion which prevents excessive motion of lid in a direction opposite to the first direction once the aperture is substantially covered, the front portion defining a groove configured to receive the lip when the lid is in the closed position.