In swimming practice, short flippers should be used. Medium and long flippers are used for snorkeling and diving. Generally, the long flippers are only suitable for freestyle, butterfly and backstroke. For beginners, wearing the short flippers can help them find the feeling of kicking quickly, or they can use the power raised when wearing the flippers to draw water to distract the attention of kicking, and focus on other movements such as rowing, air exchange, etc., which is not used in breaststroke practice.
This is my short flipper. This kind of short flipper is different from the long one. It can also be used when swimming breaststroke. Finis also has a kind of flipper like this, but there is no opening in the front. It's especially hard to grind feet. It's uncomfortable to wear.

Although this kind of fins can be worn when breaststroke, there is still a feeling of not being able to push on the water. So I think it's better not to wear flippers when swimming breaststroke. I can't find the feeling. But when I study the other three swimming postures, I will definitely get twice the result with half the effort. When I swim normally or do butterfly diving, I will also scratch forward. The only thing I need to pay attention to when I use short flippers is not to form a psychological dependence on the flippers, because the speed will slow down after I take off the flippers Many, there will be no small psychological gap, this is my little real experience.