There the dimensional series are indicated by a combination of three symbols.

那里的尺寸系列包含三种符号。

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TUBE TYPE: This may be one, two, or three alphanumerics or symbols.

管型：这可能是一个，两个或三个字母，数字或符号。

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TUBE TYPE: This may be one, two, or three alphanumerics or symbols.

管型：这可能是一个，两个或三个字母，数字或符号。

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