The present invention describes a stackable container system comprising: a plurality of containers (103), each container having an opening at a top thereof and a bottom, the opening at the top separated from the bottom by a side wall and wherein each container includes: a first part (202b) of a bayonet mount formed within a part of the side wall which depends from the bottom of the container； and a first threaded portion located on the side wall at the top of the container； and a plurality of lids (104), each lid having a top surface and a side wall and wherein each of the lids includes: a second part (202a) of the bayonet mount formed in a side of a projection extending above the top surface of the lid； and a second threaded portion located inside the side wall of the lid and below the second part of the bayonet mount such that, when the stackable container system is assembled from the containers and lids, the second threaded portion is offset in stack height relative to the second part of the bayonet mount； wherein: the containers and lids are configured to allow any of the lids to be used on any of the containers； the bottom of each container allows the container to be interlocked with the top of each lid using the bayonet mount； each lid and each container are attachable through threaded engagement of the first and second threaded portions； the first part of the bayonet mount of the container is twistable into the second part of the bayonet mount of the lid to lock the lid to the bottom of the container； and the bayonet mount comprises a pocket that holds the first part of the bayonet mount in place after being twisted into the second part of the bayonet mount.
