The Yonex nylon shuttlecocks are precision products made in Japan. They have similar flight characteristics to a natural feather shuttlecock and are available in various qualities and speeds. For halls with poor visibility and/or bright backgrounds, we recommend yellow shuttlecocks. In Switzerland, the medium speed (blue) is typically used. Other speeds are only permitted or recommended at higher altitudes or under extreme weather conditions (temperature, humidity). In badminton, the speed of the shuttlecock used is defined by the rules or the referee. This is only altered by external geographical or meteorological circumstances. The skill level or preferences of the players do not play a role in this, at least from a regulatory standpoint. However, at lower levels, players often use slower shuttlecocks as they are easier to control, or faster shuttlecocks to hit from baseline to baseline. The number next to the designation "Mavis" indicates the quality of the shuttlecocks; the higher the number, the better the product. There are different qualities among the plastic shuttlecocks. The speeds of the shuttlecocks are categorized as slow (green), medium (blue), and fast (red). These designations apply only to Yonex nylon shuttlecocks. Mavis-10 and Mavis-350 are also available as yellow shuttlecocks, as they are more visible against bright and/or diffuse backgrounds. They are now even used more frequently than traditional white shuttlecocks.