Symbol Explanation:

Short tone (one second).■■■ Long sound (over 3 seconds); Whistle sound within the command with an interval of 2-3 seconds, and the interval between commands is over 30 seconds (e.g., to repeat the command, you need to wait over 30 seconds).

Communication (T):■■■ (long sound) is used for voice communication among teams to determine the direction of each other's whistle signals. After receiving a whistle command, it is used to indicate that the command has been received (similar to shouting 'Hey~~~~~').

集合（U）：●● ■■■ (two short and one long) Assemble towards the whistle direction (similar to the shout "Assemble!!!")

前进（V）：● ■■■ (一?桃怀ぃ? 休息时发出代表全队出发、行进中发出代表加速前进 （同喊话 冲啊~~~~ 相似）

Front of the queue (W):●■■■ ■■■ (一短两长) is used when the distance of the team's march is too long, requiring the front team to wait for the rear team (similar to the shout "Please wait~~~ wait~~~~")

Support requested (S):●● ● (Three short beeps) When encountering difficulties and needing help, send out this signal. The receiver responds with a communication tone (T) to indicate that they will come to assist (similar to shouting out 'urgent! urgent! urgent!')

SOS：●"● ● ■■■ ■■■ ■■■ ● ● ● （三短 三长 三短） 这是国际通用的SOS代码，请大家熟记" This is the international SOS code, which is widely recognized. Please remember it well.

【Brand】：OK Whistle

【型号】：大OK比赛用

【Material】: Eco-friendly PVC material

【适用】：田径球赛等裁判用

Dear customer, thank you for your attention and support. In order for us to communicate better and have a pleasant transaction, please take a few more minutes to read the following text before shopping. I wish you a happy shopping experience!
How to Place an Order
① Contact us via online platforms and telephone.
Please contact us by phone and describe your requirements in detail!
Section Two: About the Price
All products in our factory are for reference only. If you need to customize, please consult with our customer service.All quantities are offered at a discount.

Lanshan District, Linyi City, Donglin Sports Goods Factory is a professional company that produces and processes products, with a complete and scientific quality management system. The integrity, strength, and quality of Donglin Sports Goods Factory products have gained recognition in the industry. We welcome friends from all walks of life to visit, guide, and conduct business negotiations.

Name: Donglin Sports Equipment

Contact: Zhu Kongji

Address: Lanshan District, Linyi City