Linksys WTR54GS v1

Overview
WTR54GS v1.0 devices have serial numbers starting with SJH0. But per the DD-WRT forums, some UK v2.0 models may also have the same serial prefix.

WTR54GS on the DD-WRT wiki


 * On the DD-WRT forums

WRT54G series on Wikipedia

"4900QZ00D" is silkscreened on the board in the FCC photos.