Part J8438A is compatible in the following Models:

HPE ProCurve 2900 Switch series

ProCurve 2900-24G Switch - J9049A
ProCurve 2900-48G Switch - J9050A

HPE Switch X2 Modules

ProCurve Switch vl 1-port 10-GbE X2 Module - J8766A

HPE X2 ER Transceivers

ProCurve 10-GbE X2-SC ER Optic Transceiver - J8438A