flotation collar

• 安全环状浮袋

flotation collar的用法和样例：

例句

1. Install flotation bags in non-inflatable craft, securely fixed in each end, designed to displace as much water as possible.
   在非充气的船上安装一些安全环状浮袋，固定在每一端，设计用于船入大量水的情况。