Carries US Patent on the diffuser design. Inside diameter of .875" and is recommended for DC applications only. It uses anywhere from 25-30 + CFH of Argon flow. Recommended for 3/32" tungsten size and carries a 180 amp rating on constant amperage. It can go higher if using pulse settings. Hand made in the USA of Borosilicate laboratory grade glass. Due to the nature of the Glass “walking the cup“ is not recommended.