The Hakko T33-D5 Ultra Heavy Duty Chisel Soldering Tip measures 5mm x 13mm. Use with the Ultra Heavy Duty Soldering Iron. The iron is used with the Ultra Heavy Duty UHD Soldering Station which is the ideal soldering station for extremely large mass components, such as high current inductor coils, heat sinks, large transformers, shields, and other difficult solder applications where there is a significant amount of thermal inertia that must be overcome, enabling you to solder some of the most challenging solder joints.