The Cisco OC-12c/STM-4c POS Shared Port Adapter is single-height SPA that installs into one SIP subslot. The 1-Port OC-12c/STM-4 POS SPA with a small form-factor pluggable (SFP) optical transceiver module provides SONET and SDH network connectivity with a bandwidth of 622.08 Mbps.