An adapter used in a cable raceway used in cabling for data communication in the telecommunication industry, the adapter comprising: a main housing; at least one first connection part disposed on the main housing for connecting the adapter to the cable raceway; at least one second connection part disposed on the main housing for connecting at least one distribution module to the adapter; and at least one distribution module for connecting with cables in the adapter and introducing patch cords, the at least one distribution module directly mounted in the adapter; wherein the main housing comprises a flat bottom wall and a plurality of sidewalls vertically extending from the bottom wall, wherein said plurality of sidewalls comprises a first sidewall and an opposing second sidewall, which together with the bottom wall form two U-shaped configurations corresponding to a U-shaped cross-section of the cable raceway, wherein the first sidewall and the second sidewall each is provided with at least one window for exposing a portion of the distribution module, the plurality of sidewalls also including a third sidewall and an opposing fourth sidewall, the third and fourth sidewalls (114, 115) each including a main wall portion being vertical with respect to the first sidewall and the second sidewall and an extension wall portion extending from the main wall portion; wherein the bottom wall includes bottom wall extension portions to, together with the extension wall portions of the third and fourth sidewalls, form a U-shaped configuration corresponding to the U-shaped cross-section of the cable raceway; the at least one first connection part is disposed on at least one sidewall, wherein the first connection part is at least disposed on one of the U-shaped configurations; wherein the first connection part is at least disposed on the U-shaped configuration formed by the third side wall and the bottom wall; and the at least one second connection part is disposed on corresponding sidewalls, wherein the second connection part is at least disposed on the first sidewall and/or the second sidewall. a main housing; at least one first connection part disposed on the main housing for connecting the adapter to the cable raceway; at least one second connection part disposed on the main housing for connecting at least one distribution module to the adapter; and at least one distribution module for connecting with cables in the adapter and introducing patch cords, the at least one distribution module directly mounted in the adapter; wherein the main housing comprises a flat bottom wall and a plurality of sidewalls vertically extending from the bottom wall, wherein said plurality of sidewalls comprises a first sidewall and an opposing second sidewall, which together with the bottom wall form two U-shaped configurations corresponding to a U-shaped cross-section of the cable raceway, wherein the first sidewall and the second sidewall each is provided with at least one window for exposing a portion of the distribution module, the plurality of sidewalls also including a third sidewall and an opposing fourth sidewall, the third and fourth sidewalls (114, 115) each including a main wall portion being vertical with respect to the first sidewall and the second sidewall and an extension wall portion extending from the main wall portion; wherein the bottom wall includes bottom wall extension portions to, together with the extension wall portions of the third and fourth sidewalls, form a U-shaped configuration corresponding to the U-shaped cross-section of the cable raceway; the at least one first connection part is disposed on at least one sidewall, wherein the first connection part is at least disposed on one of the U-shaped configurations; wherein the first connection part is at least disposed on the U-shaped configuration formed by the third side wall and the bottom wall; and the at least one second connection part is disposed on corresponding sidewalls, wherein the second connection part is at least disposed on the first sidewall and/or the second sidewall.