Allstate safety traction control for mounting in the trunk of a car, or in/under the bed of a pick-up truck.
(Weighs about 70 lbs.)

Bought a pair new in 1976.
One has always been mounted in the trunk of the family car.
(This one is out of my wife's trunk!)

Has a gyroscope system inside, with a weight that transfers from one side to the other, when the vehicle's rear starts to slide!

They were installed in some police cars back in the 70's - 80's.

A lot were/ARE used (and racer endorsed!) in the rear of race cars.

Still being used @ some dirt tracks in Ohio this year!
(I'm an old racer/mechanic, visiting with car builders.)
Some tracks have made them illegal, so they were/are hidden in big rear frame tubes.

Helps very noticeably for WINTER driving!
Mine were bought new, and have NEVER been in a race car!

I also have another one from my pick-up that's a little rusty on the top for $15.

TEXTS ONLY PLEASE!
(I have goofy hrs. and I'm hard to get a hold of.)