An output assembly for a print particle replenishment device for a host device, the print particle replenishment device comprising: a bulk print particle reservoir; an output neck to output print particles, wherein the output neck comprises a protruding portion, a cutout, and a neck wall, and is configured to fit to a print particle receptacle, wherein the print particle replenishment device is configured to be turned, wherein the turning motion is configured to move a cover of a host device receptacle input opening to allow print particles to flow into the input opening of the host device; the output assembly comprising: a first surface comprising a sliding member, wherein the sliding member comprises a channel and a first notch, wherein the channel is offset from a rotating axis of the output assembly, wherein the first notch is offset from the rotating axis of the output assembly and extends to an outer edge of the sliding member; a second surface comprising a cover member configured to maintain a static position with respect to a rotation of the sliding member, wherein the cover member comprises a second notch that is offset from the rotating axis of the output assembly and extends to an outer edge of the cover member, wherein when the print particle replenishment device is in an undocked position with the host device, the first notch is configured to interlock with a port cover of the host device, and the second notch is configured to align with the port of the host device; wherein the first surface is positioned relatively upstream of an end of the output neck, wherein the first surface is configured to align to an input opening of the host device, wherein the second surface is positioned at a downstream end of the output neck and is configured to align with the input opening of the host device, wherein the output assembly is adapted so that in a closed condition, the channel of the first surface is not aligned with the input opening of the host device, and so that in an open condition, the channel of the first surface is aligned with the input opening of the host device; and integrated circuitry comprising contact pads at a side wall of the print particle output assembly. a bulk print particle reservoir; an output neck to output print particles, wherein the output neck comprises a protruding portion, a cutout, and a neck wall, and is configured to fit to a print particle receptacle, wherein the print particle replenishment device is configured to be turned, wherein the turning motion is configured to move a cover of a host device receptacle input opening to allow print particles to flow into the input opening of the host device; wherein the print particle replenishment device is configured to be turned, wherein the turning motion is configured to move a cover of a host device receptacle input opening to allow print particles to flow into the input opening of the host device; the output assembly comprising: a first surface comprising a sliding member, wherein the sliding member comprises a channel and a first notch, wherein the channel is offset from a rotating axis of the output assembly, a first surface comprising a sliding member, wherein the sliding member comprises a channel and a first notch, wherein the channel is offset from a rotating axis of the output assembly, wherein the first notch is offset from the rotating axis of the output assembly and extends to an outer edge of the sliding member; a second surface comprising a cover member configured to maintain a static position with respect to a rotation of the sliding member, wherein the cover member comprises a second notch that is offset from the rotating axis of the output assembly and extends to an outer edge of the cover member, wherein when the print particle replenishment device is in an undocked position with the host device, the first notch is configured to interlock with a port cover of the host device, and the second notch is configured to align with the port of the host device; wherein the first surface is positioned relatively upstream of an end of the output neck, wherein the first surface is configured to align to an input opening of the host device, wherein the second surface is positioned at a downstream end of the output neck and is configured to align with the input opening of the host device, wherein the output assembly is adapted so that in a closed condition, the channel of the first surface is not aligned with the input opening of the host device, and so that in an open condition, the channel of the first surface is aligned with the input opening of the host device; and wherein when the print particle replenishment device is in an undocked position with the host device, the first notch is configured to interlock with a port cover of the host device, and the second notch is configured to align with the port of the host device; wherein the first surface is positioned relatively upstream of an end of the output neck, wherein the first surface is configured to align to an input opening of the host device, wherein the second surface is positioned at a downstream end of the output neck and is configured to align with the input opening of the host device, wherein the output assembly is adapted so that in a closed condition, the channel of the first surface is not aligned with the input opening of the host device, and so that in an open condition, the channel of the first surface is aligned with the input opening of the host device; and integrated circuitry comprising contact pads at a side wall of the print particle output assembly.