PIT CART is correct it's part of the electronic air bleeders.
Jeff Swindell designed them. There is a comparison video on his website.
Best thing about the Swindell Bleeders is they are pretty much maintenance free. Worst thing about them is the $1500 price tag. The Conroy Pneu diaphragm system which is likely the second best bleeder out there the cost is $350 but have to clean and adjust them often.