Star Trek Next Generation Poster Seventh Anniversary. This poster is 16 inches by 24 inches approximately. It is in mint condition. Conversion Table: Inches to Centimeters. 12 x 12 inches is approximately 30 x 30cm. 11 x 17 inches is approximately 28 x 43cm. 12 x 18 inches is approximately 31 x 46cm. 18 x …