A printing fluid cartridge comprising: a front side; a rear side positioned opposite the front side with respect to a front-rear direction; an upper side; a lower side positioned opposite the upper side with respect to an up-down direction which is perpendicular to the front-rear direction; a tubular fluid supply portion positioned at the lower side of the front side; a pivotable member comprising a front end portion, a rear end portion and a shaft comprising a pivot point, and configured to pivot about the shaft extending in a left-right direction which is perpendicular to the front-rear direction and the up-down direction, wherein the pivot point is positioned at the upper side and the rear end portion is positioned at the rear side; characterized by a light attenuating portion protruding from the upper side of the front side and configured to attenuate light traveling in the left-right direction; and an electrical interface (75, 76, 77) positioned between the pivotable member and the light attenuating portion with respect to the front-rear direction and comprising a surface extending in the front-rear direction and the left-right direction, a stopper comprising an engagement surface extending in the up-down direction and the left-right direction, wherein the pivotable member is positioned in rear of the electrical interface with respect to the front-rear direction, and wherein the front end portion extends from the shaft toward the engagement surface and the rear end portion extends from the shaft toward the rear side; wherein the stopper is positioned between the pivotable member and the electrical interface with respect to the front-rear direction, wherein an upper end of the light attenuating portion is positioned below the electrical interface with respect to the up-down direction. a front side; a rear side positioned opposite the front side with respect to a front-rear direction; an upper side; a lower side positioned opposite the upper side with respect to an up-down direction which is perpendicular to the front-rear direction; a tubular fluid supply portion positioned at the lower side of the front side; a pivotable member comprising a front end portion, a rear end portion and a shaft comprising a pivot point, and configured to pivot about the shaft extending in a left-right direction which is perpendicular to the front-rear direction and the up-down direction, wherein the pivot point is positioned at the upper side and the rear end portion is positioned at the rear side; characterized by a light attenuating portion protruding from the upper side of the front side and configured to attenuate light traveling in the left-right direction; and an electrical interface (75, 76, 77) positioned between the pivotable member and the light attenuating portion with respect to the front-rear direction and comprising a surface extending in the front-rear direction and the left-right direction, a stopper comprising an engagement surface extending in the up-down direction and the left-right direction, wherein the pivotable member is positioned in rear of the electrical interface with respect to the front-rear direction, and wherein the front end portion extends from the shaft toward the engagement surface and the rear end portion extends from the shaft toward the rear side; wherein the stopper is positioned between the pivotable member and the electrical interface with respect to the front-rear direction, wherein an upper end of the light attenuating portion is positioned below the electrical interface with respect to the up-down direction.