This tube is used in some rotary conversions. Inner span is  2.15"  Outer span is 3.35"  Tube OD is .600"  Tube ID is .560"

Used in tenor trombone wraps

 This is a tenor trombone 45 wrap tube 

These tubes are typically used in pairs. 80 tubes replace the 45 and 90 tubes on an axial conversion.  Use 2 for a cleaner look, and a more open softer curve for air flow. 

 This is a tenor trombone small 90 wrap tube