This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anaesthetic equipments, Subject name: Anaesthesia
Fixed performance device is 
Select and explain. 
A. Ventury mask, B. Nasal cannula, C. Simple mask, D. Non rebreathing mask
A: Ventury mask
Answer: A: Ventury mask 
Explanation: venturi mask is a device used to deliver designated oxygen concentration to patients on controlled oxygen therapy. It is designed with wide bore tubes with various colour adapters. Each colour code responds to the precise oxygen concentration and specific litre flow.