Armed Free Trader (Traveller HERO)

From the introduction:

One of the most common starships in the Imperium, the Type A free trader has remained unchanged for centuries. Built throughout the Imperium and beyond by the thousand, this small 200 ton cargo ship continues to ply the trade routes and mains, picking up small cargoes and engaging in speculative trade. The primary variant of the free trader is the Jump-2 capable far trader, also used throughout Known Space. Enterprising merchant captains starting their own businesses usually start with a free trader and work their way up from there. The free trader is a simple, cheap design with minimal specifications that will be built for centuries to come.