[Professional model] 3 meters for students (suitable for one person) [Professional model] 4 meters for students (suitable for 1-2 people) [Professional model] 5 meters for students (suitable for 2-3 people) [Professional model] 6 meters for students (suitable for 3-4 people) [Professional model] 7 meters for students (suitable for 4-6 people) [Professional model] 8 meters for students (suitable for 7-8 people) [Professional model] 9 meters for students (suitable for 8-9 people)[Professional model] 10 meters for students (suitable for 9-10 people) [Professional model] 12 meters for students (suitable for 10-15 people) [Professional model] 15 meters for students (suitable for 15-18 people) [Upgraded model] 3 meters for students (suitable for one person) [Upgraded model] 4 meters for students (suitable for 1-2 people) [Upgraded model] 5 meters for students (suitable for 2-3 people) [Upgraded model] 6 meters for students (suitable for 3-4 people)[Upgraded model] 7 meters for students (suitable for 4-6 people) [Upgraded model] 8 meters for students (suitable for 7-8 people) [Upgraded model] 9 meters for students (suitable for 8-9 people) [Upgraded model] 10 meters for students (suitable for 9-10 people) [Upgraded model] 12 meters for students (suitable for 10-15 people) [Upgraded model] 15 meters for students (suitable for 15-18 people)
