Members of the Congressional Black Caucus are visiting Silicon Valley to push the tech industry to improve diversity.

The visit is part of the group’s Tech 2020 initiative, which calls on companies to boost the numbers of African-Americans they employ.

Rep. Barbara Lee (D-Calif.), whose Oakland district borders the country’s tech hub, expressed frustration with the industry’s efforts.

“Silicon Valley’s economy is booming but we still don’t have the parity and equity in terms of racial inclusion,” Lee told The Hill on Monday. “The lack of understanding of why racial equity is important is mind-boggling to me.”

Lee declined to identify the companies she was referring to.

She has been joined by other Black Caucus members, including Reps. Gregory Meeks (D-N.Y.), G.K Butterfield (D-N.C.) and Maxine Waters (D-Calif.), on the trip.

The lawmakers have met with Apple and PayPal and on Tuesday will meet with representatives from other companies including Facebook, Twitter and Airbnb.

Lee said that lack of diversity is hurting companies.

“I think from a company perspective, it helps with their growth, it’s economically beneficial to have a diversity of perspectives,” she said.

“We have also moral obligation to make sure there is an equality of opportunity for everyone.”