Blackburn Mars
Mars Magnetic Light

$15

This light has a versatile mounting mechanism: it can magnetically clip to fabrics such as backpack and messenger bag straps, and it can also mount to seatposts and frames by a silicone band.
Mars 4.0

$25

Mars 3.0

$19

In addition to five red LEDs, this light has two amber side LEDs for increased visibility.
Mars 1.1

$15

3-LED light with steady, flash, and chase modes.