| 摘要 |
An electric control or signaling device to be assembled through an opening formed in a wall, and including a tubular metal body which is to engage with a first surface of the wall, wherein the body includes a threaded cylindrical portion to be inserted into the opening and an attachment device including a metal clamping ring to be screwed onto the threaded cylindrical portion of the body to attach the control or signaling device through the opening, and a metal attachment plate to be applied against a second surface of the wall opposite the first surface by the clamping ring.
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