economy dual-band whip is an 18" cellular lookalike with open "pig squiggle" phasing coil in the center. It has a 3/8-24 thread and you can get the whip only for about $7 or complete with a 3" mag mount and coax termination with your choice of BNC or PL259 connector for under $20. I have several as spare and loaner antennas for our RACES equipment cache, which are used several times a year for drills and callouts and have been extremely pleased with them.
Sweeping these on my MFJ-469 I have found that they work OK outside the ham bands without retuning. In addition to being 1.5:1 or less across the FM portions of the 2m and 70 cm ham bands, on a metal vehicle they also show VSWR under 2:1 on high-band VHF, VHF marine band, MURS, the 453-465 MHz public safety bands and GMRS. These are only unity gain, but very broad banded, rugged and inexpensive. Everyone should have one of these in their "Go Kit" as a spare antenna.
73 de KE4SKY
Virginia RACES State Training Officer