A support assembly for supporting a flexible duct includes a radius strap for maintaining the desired angle of bend for the flexible duct. The belt-retractor spring-cassette housing can be installed in a particularly simple and therefore cost-effective manner. The set of reference documents is updated with the found documents that are most relevant to the domain. In some examples, the frame andor wheels are also operable to transition to a longer wheel base in the second use mode. The label may further be provided in roll form mounted on a release liner. The system can be configured for environments ranging from dense urban, urban, suburban, rural, mountain to low traffic or isolated roadways.