A connector (100) includes an insulative housing (1) having a receiving slot (121) formed therein and a post (1221) protruding forwardly towards the receiving slot (121); a set of contacts (2) retained in the insulative housing; an optical module (3) for transmitting optical data and being movably received in the receiving slot along a front-to-back direction; and a compression coil spring (4) sandwiched between the insulative housing and the optical module, and having a front end for biasing the optical module (3) forwardly and a rear end for being retained on the post (1221).