The DRO-550 PCB kit includes the following comonents:

• DRO-550 PCB with all surface mount components installed on a modern assembly line
• All through-hole components listed in the bill of materials including GREEN LEDs, key caps, buzzer, switches, and headers

To complete your DRO-550, you will need an overlay, enclosure, power supply, cables that are suited for your installation, and scales.  See the Enclosure Parts section on the bill of materials for a list of these needed components.