"Air Spring Helper Kit"
I added these air pillows to my rear springs on my Nissan Altima. They were very easy to install and work about as well as you would expect for a $100 upgrade.
They claim that adding these air pillows to your springs and inflating them to 35 psi adds about 1000 lbs of carrying capacity to your springs so they aren't bottoming out on speed bumps etc.
I'm a regular customer, not a paid review. I bought this for myself and just doing this review so any Altima owners out there have a sense of what its all about.
I purchased mine on the phone from SD Truck springs. They are branded firestone. They are also for saie by etrailer.com but more expensive there than SD Truck Springs.
https://www.firestoneip.com/kit-searc...
Firestone Coil Rite: 4105 - Rear Kit
Kit Number: W237604105
Replacement Air Spring: W237606013