J4858C: HP – Procurve Gigabit 1000 Base SX mini Gbic The HP J4858C is a small form-factor pluggable (SFP) Gigabit SX transceiver that provides a full-duplex Gigabit solution up to 550m on multimode fiber. Leave a Reply Cancel reply Your email address will not be published. Required fields are marked *Comment Name * Email * Website Save my name, email, and website in this browser for the next time I comment.