I'm an old fashioned guy (my cars had bias-ply tires. Glass belted was a big deal.). I can't tell the difference in radials properly inflated and 10lbs low.

The senders are electronic modules inside the wheels, not the valve stems and caps, though these are included.

If you substitute non-tpms valve stems you'll have a perpetual light on your dash, nagging you like Gladys Kravitz. No one here has been clever enough to disable the light: a piece of black tape seems to be the SOP to disable it.

 

Hard to eyeball them from behind the wheel.

 

I have a 2012 Fit and my TPMS went on last week. Done mine for free. It was still under the 3 year 36,000 miles warranty.