  We show that quantum resistance standards made of transferred graphene reach
the uncertainty of semiconductor devices, the current reference system in
metrology. A large graphene device (150 \times 30 \mum2), exfoliated and
transferred onto GaAs, revealed a quantization with a precision of (-5.1 \pm
6.3) \times 10-9 accompanied by a vanishing longitudinal resistance at current
levels exceeding 10 \muA. While such performance had previously only been
achieved with epitaxially grown graphene, our experiments demonstrate that
transfer steps, inevitable for exfoliated graphene or graphene grown by
chemical vapor deposition (CVD), are compatible with the requirements of high
quality quantum resistance standards.
