Child-resistant closure

A container system comprising:

• a container body having a base, at least one side wall extending upwardly from the base, and a rim disposed about the base, wherein the rim defines an open end of the container;
• a lid configured to close the open end of the container;
• and
• a ring disposed circumferentially about the at least one sidewall between the rim and the base,
• wherein the lid and ring form a locking system, the locking system comprising:
• at least one post comprising a neck and a head extending from one of the lid or the ring, wherein the head defines a diameter larger than the neck;
• and
• a track disposed at least circumferentially about one of the lid or the ring, the track comprising at least one insertion point and at least one retention region, wherein the insertion point defines a cavity configured to receive the head and the neck of the at least one post, and wherein the at least one retention region defines a head-receiving portion and a neck-receiving portion, wherein the neck receiving portion defines a smaller width than the head;
• and
• wherein the ring and lid are circumferentially rotatable between a locked position and an unlocked position, wherein in the locked position the at least one post is positioned within the at least one retention region, and in the unlocked position the at least one post is positioned within the at least one insertion point.