It's definitely a ball lock but it's hard to tell how tall it is from that perspective. If it's about 23" tall, it's a 5 gallon and worth about $25. If it's about 8" shorter, it's a 2.5 or 3 gallon and worth about $80. The regulator is worth about $35.
Sightglass, Refractometer, Ball Valve, Weldless bulkhead, Thermometer, Decals, Stainless Steel Fittings, Compression Fittings, Camlock Quick Disconnects, Scale, RIMS tube, Plate Chiller, Chugger Pump, Super Clear Silicone Tubing, and more!