Quick sphere with easy snap engagement and audible indicator

A device comprising a retro-reflective marker comprising:

• a core comprising:
• a body portion, and
• a mounting recess extending into the body portion of the core,
• wherein the mounting recess comprises one or more flexible snap-on interior engagement structures configured to releasably engage one or more complementary exterior engagement structures of a mounting post when the retro-reflective marker is in a secured configuration on the mounting post,
• wherein releasable engagement of one or more interior engagement structures of the mounting recess with one or more complementary exterior engagement structures of the mounting post generates an audible clicking sound,
• wherein multiple audible clicks are generated as the mounting post axially extends into the mounting recess, and
• wherein, cessation of the audible clicking sound indicates that the retro-reflective marker is in a secured configuration on the mounting post.

A device comprising a retro-reflective marker comprising:

• a core comprising:
• a body portion, and
• a mounting recess extending into the body portion of the core,
• wherein the mounting recess comprises one or more interior engagement structures configured to releasably engage one or more complementary exterior engagement structures of a mounting post when the retro-reflective marker is in a secured configuration on the mounting post,
• wherein the mounting recess comprises internal gaps between one or more interior surface regions of the mounting recess and one or more protruding surface regions of a mounting post when the retro-reflective marker is mounted in the secured configuration on the mounting post, and
• wherein the retro-reflective marker and the mounting post have a stop contact between a bottom surface of the retro-reflective marker and a support surface of the mounting post and this is the only stop contact between the retro-reflective marker and the mounting post.