Sen. Chuck Grassley, R-Iowa, sent a letter to the Air Force Tuesday demanding to know why an air base in California is purchasing hot cups that cost $1,280 each.

Grassley’s letter to Air Force Secretary Heather Wilson cites a Fox News article that reported last week that the 60th Aerial Squadron at Travis Air Force base over the past three years spent nearly $56,000 on cups that can reheat liquids during flight.

This year alone, 25 cups were purchased at a cost of $1,280 for each cup.

“This latest example of reckless spending of taxpayer dollars gives me no confidence that the Air Force is taking real steps to reduce wasteful spending practices. This report also heightens my concern that the DOD Office of Inspector General is not prioritizing oversight of wasteful spending,” Grassley wrote.

The squadron reported that the cups have handles that break easily when dropped. Since spare parts are not available, the whole cup has to be replaced.

A team at Travis is using 3D printing to create stronger handles.

“While it is laudable that the men and women at Travis Air Force Base took action to curb this wasteful spending, this does not address the puzzling question of why the Air Force is buying these cups at such a high cost to begin with,” Grassley said.

He pointed out that according to officials at Travis, each cup cost $693 in 2016.

The Air Force and Travis air base did not immediately respond to requests seeking comment.