A printing fluid cartridge configured to be inserted into a cartridge mounting portion in an insertion direction in an upright position against a biasing force exerted in a removal direction opposite the insertion direction, the printing fluid cartridge in the upright position has a width in a width direction, a height in a height direction, and a depth in a depth direction, wherein the width direction, the height direction, and the depth direction are perpendicular to each other and the depth direction is parallel with the insertion direction, the height direction corresponds to the gravitational direction, and the printing fluid cartridge in the upright position comprising: a front face oriented toward the insertion direction when the printing fluid cartridge is inserted into the cartridge mounting portion; a rear face positioned opposite the front face with respect to the insertion direction and oriented toward the removal direction when the printing fluid cartridge is inserted into the cartridge mounting portion; a front wall, a rear wall opposite the front wall with respect to the insertion direction and a top wall connected to upper ends of the front wall and the rear wall, wherein an outer face of the front wall is the front face of the ink cartridge and an outer face of the rear wall is the rear face of the ink cartridge;a chamber positioned between the front face and the rear face and configured to store printing fluid therein; a printing fluid supply portion positioned at the front face and configured to supply the printing fluid from an interior of the chamber to an exterior of the chamber; an electrical interface (75, 76, 77) configured to allow an electrical access to an integrated circuit provided to the printing fluid cartridge, the electrical interface being positioned between the front face and the rear face with respect to the insertion or removal direction; an engagement portion for retaining the printing fluid cartridge in the cartridge mounting portion against the biasing force, the engagement portion being positioned at a top wall side of the ink cartridge and comprising an engagement surface; and a pivot member having a front end portion being configured to be positioned in a first position such that the front end portion is positioned below an upper end of the engagement surface, and the pivot member is positioned at a rear portion of the top wall such that the engagement surface is more forward in the insert direction than the front end portion. a front face oriented toward the insertion direction when the printing fluid cartridge is inserted into the cartridge mounting portion; a rear face positioned opposite the front face with respect to the insertion direction and oriented toward the removal direction when the printing fluid cartridge is inserted into the cartridge mounting portion; a front wall, a rear wall opposite the front wall with respect to the insertion direction and a top wall connected to upper ends of the front wall and the rear wall, wherein an outer face of the front wall is the front face of the ink cartridge and an outer face of the rear wall is the rear face of the ink cartridge;a chamber positioned between the front face and the rear face and configured to store printing fluid therein; a printing fluid supply portion positioned at the front face and configured to supply the printing fluid from an interior of the chamber to an exterior of the chamber; an electrical interface (75, 76, 77) configured to allow an electrical access to an integrated circuit provided to the printing fluid cartridge, the electrical interface being positioned between the front face and the rear face with respect to the insertion or removal direction; an engagement portion for retaining the printing fluid cartridge in the cartridge mounting portion against the biasing force, the engagement portion being positioned at a top wall side of the ink cartridge and comprising an engagement surface; and a pivot member having a front end portion being configured to be positioned in a first position such that the front end portion is positioned below an upper end of the engagement surface, and the pivot member is positioned at a rear portion of the top wall such that the engagement surface is more forward in the insert direction than the front end portion.