Characteristics：
Swiss Spiro Standard Arc seam, combined tightly, gas density is excellent.
The Helix spacing is small (p=120mm), the intensity is especially high.
The use of flying-type cutting, no burrs, construction safety.
In line with the United States Sheetmetal Association (SMACNA), the United States (ASHRAE) and Germany (DIN) Spiral duct manufacturing standards.

Characteristics：
Swiss Spiro Standard Arc seam, combined tightly, gas density is excellent.
In the middle of the spiral seam, there are three Swiss Spiro reinforcing type reinforcing ditch.
The use of flying-type cutting, no burrs, construction safety.
High strength, light weight, convenient construction.
It is applicable to the use of the wind duct and the construction pretension beam with weight concern.
In line with the United States Sheetmetal Association (SMACNA), the United States (ASHRAE) and Germany (DIN) Spiral duct manufacturing standards.

Characteristics：
Swiss Spioro Standard arc seams, combined tightly.
The use of flying-type cutting, no burrs, construction safety.
In the middle of the spiral seam, there are three Swiss Spiro reinforcing type reinforcing ditch.
High strength, light weight, convenient construction.
Punching rate 30% ~ 40%.
With external pipe caliber production.
Suitable for use in double helix tube or silencer tube.

Characteristics：
With excellent insulation and silencing effect.
Beautiful appearance, the most suitable for the air duct exposed place.
The insulation layer is sandwiched between two layers, and is not shed by years long.

Characteristics：
With excellent insulation and silencing effect.