1. 12 years OEM Standard different 2. Adaptors with different feeders 3.Accessories interchangeable with Panasonic's

OTC QTB-200A welding torch

Rating: 200A CO2   180A mixed gas, 60% duty cycle, wires: 0.8-1.2mm 

OTC QTB-350A  welding torch

Rating: 350A CO2   300A mixed gas, 60% duty cycle, wires: 1.0-1.4mm

OTC QTB-500A welding torch

Rating: 500A CO2   420A mixed gas, 60% duty cycle, wires: 1.2-1.6mm