Uniweld S25 Soft Flame Air/Acetylene Tip The soft flame produces a precise 2700°F target heat and is excellent for soldering copper tubing A time tested flame tool with over 50 years of proven performance Withstands the most abusive of field conditions A favorite of plumbersSize 5 2700°F Target heat 1/2" to 1-1/2" Copper tube soldering capacity 1/2" to 3/4" Copper tube brazing capacityK37, K38