Need to run 4" duct to vent my 3d printers, wanted to run along the walls but didn't want to drill holes and wanted to be able to remove later. Designed the bracket with holes if you want to use screws or Command Brand removable tape model BATH22-ES. Included a print file to print 1 or 4 at a time. They are designed to need no support. I used PLA+ but just about anything will work.

Print Settings

Material: PLA or PLA+ or ?
Layer height: 0.2 mm
Perimeters: 3
Top layers: 4 layers
Infill: 15% adaptive cubic
Supports: no