Back when Ethernet transceivers were not on board…

This is model M0437 it was the best way to connect your Mac to a network.

Let’s look at the specs:

CONNECTORS: Apple Ethernet 14-pin, RJ-45 receptacle 3 meter RJ-45 patch cable included

WIRING: Unshielded twisted-pair (telephone style)

MAX. CABLE LENGTH: 100 meters

SIGNALING STANDARD: IEEE/ISO 802.3 10Base-T

SIGNALING SPEED: 10Mbps

NETWORK STATUS: LEDs indicate link integrity and data activity

SELF-CORRECTION: Automatic correction of receive wiring polarity errors

Compatible with any Macintosh with a AAUI Ethernet port

Wow! Such technology! Such Connectivity!