Does this filter come with a new housing or just the filter element?

Just the filter element. Your existing air box housing stays in place — drop the new filter in and you're done.

How often should I replace this filter?

Depends on your driving conditions. City driving with dust typically calls for replacement every 15,000–20,000 miles. Check it visually every oil change.

What makes the red media different from a standard white filter?

Red media resists clogging longer and doesn't degrade as fast when exposed to moisture and debris, which extends the life between replacements.