SUP21S保护镜片和聚焦镜片的安装（中英）

注意：

be careful:

1.更换时请注意现场环境，建议使用纸胶带防尘

1.Please pay attention to the on-site environment during replacement, and it is recommended to use paper tape to prevent dust

2.保护镜密封圈规格为：15*21*2.7

Specification of protective mirror sealing ring: 15 * 21 * 2.7

3.默认的保护镜规格为：D18*T2

3. The default protective mirror specification is: D18 * T2