Diamond SupraMax DSL642WLG v1

Diamond was later acquired by Best Data. Product page Manual

OEM SerComm, presumed to be a SerComm IP806GA/GB v2
 * There is no FCC ID on the label, but the FCC ID of the IP806GA/GB v2 has been assigned to this entry..

"4900PC10A" and "MADE IN TAIWAN" is silkscreened on the board.