Gift certificate good for one month of private and group instruction, one Black Belt Student Manual and one karate uniform and belt from United Studios of Self Defense. Martial arts classes are offered for children ages three-and-a-half and older at this Marina district studio (located at Lombard and Scott). Kids are grouped by age, with classes divided into Pre-K, Children's, Teens (separate class), and Adults. In addition to martial arts, the classes encourage social skills, good etiquette, concentration, and lots of exercise. Parents like its low-key, friendly atmosphere and the fact that it often offers family discounts and gift certificates.