Physical description
A small, sealed carton, most likely containing a tether tennis ball and, a string and elastic tether. Inscription across one face of the box: THE PERFECT/KUM-BAK/.../TENNIS SELF-TRAINER/... Across another: THIS CARTON/CONTAINS -/ONE TENNIS/AUTO COACH/CAPTIVE BALL/COMPLETE WITH/ATTACHMENTS. Materials: Rubber, Felt, String, Metal, Cardboard, Paper, Ink