The Lenovo 01PE215-RFB system board is a replacement board for the x3650 M5 server. It provides a system board option for supported x3650 M5 configurations, including the ThinkAgile SXM context referenced by Lenovo for the base FRU 01PE215.
The exact listed part number is 01PE215-RFB. Lenovo identifies base FRU 01PE215 as an x3650 M5 system board; the RFB listing likewise names the x3650 M5 system board. This confirms the part type and server family for replacement planning.