Slide rail kit

A slide rail system, comprising:

• a rack having a first side frame and a second side frame, wherein each of the first side frame and the second side frame comprises at least one post;
• and
• a slide rail kit comprising:
• a first rail having an outer side and an inner side;
• a second rail longitudinally movable relative to the first rail and adjacent to the inner side of the first rail;
• and
• a bracket device arranged on the first rail and comprising a rack mounting feature;
• wherein a recessed structure is formed at the outer side of the first rail and recessed toward the inner side of the first rail;
• wherein the post of the first side frame has a predetermined part arranged along a transverse direction of the slide rail kit and formed with a corresponding hole;
• wherein the first rail is configured to be mounted to the post of the first side frame of the rack through inserting the rack mounting feature of the bracket device along a longitudinal direction of the slide rail kit into the corresponding hole of the predetermined part, wherein when the rack mounting feature of the bracket device is inserted into the corresponding hole of the predetermined part, at least a portion of the predetermined part of the post of the first side frame is configured to be extended into the recessed structure of the first rail along the transverse direction of the slide rail kit to be accommodated within the recessed structure, and the rack mounting feature of the bracket device is adjacent to the recessed structure of the first rail.