Multistage communication concentrator

The utility model provides a multistage communication concentrator, its characterized in that: it reaches the case lid on the box that articulates corresponding to this side to have an open concentrator box in side, it is protruding that this side periphery is equipped with round annular, and the internal surface of case lid is equipped with an annular groove, and the embedded round sealing washer that is equipped with of annular groove is in the above -mentioned annular protruding insert ring connected in star and the press?the?sealing circle, what have in the box that from the top down arranges is several to the draw -in groove, whenever establishes two the relative medial surfaces at the box to the draw -in groove correspondingly, and the both sides limit of several backup pad is inlayed respectively and is established in the draw -in groove, the surface of backup pad is equipped with a plurality of installation through -holes, set firmly NCU base plate, stabiliser and power in from the top down's the back