备用二级头呼吸器

1. • backup regulator octopus

     scuba diving

Character by character

• 备(bèi)prepare
• 用(yòng)use
• 二(èr)two
• 级(jí)level
• 头(tóu)head
• 呼(hū)call
• 吸(xī)breathe
• 器(qì)device