Weng Ming-yi points to the skis 'tank-like wheel-and-belt construction and explains, "The surface area of the skis in contact with the grass is larger than the soles of a person's shoes, so there's less damage done to the grass by skiing over it than by walking on it."
翁明義手拿內包輪子、外圍皮帶，像袖珍坦克車輪子的滑草器，邊示範、邊說明：「滑草時，輪子的轉動帶動履帶，與草地直接接觸的是長約七十五公分、寬七十二公分的平滑履帶，底面積比人的鞋子大得多，對草地的損耗比人的踐踏還輕。」