These t-shirts say women are paid as much as men. Wait, what?

Today is Equal Pay Day, and to highlight the gender pay gap, the National Organization for Women (NOW) has devised a thought-provoking stunt.

Agency 22squared created a line of t-shirts ("Equalitees") for sale via online retailers including raygunsite.com; blackonblackbk.com; blackanddenim.com and woveprint. They're emblazoned, in several different designs, with the slogan "Women Now Make As Much As Men. About Damn Time." However (as you might have guessed) there's a twist: when they click on the t-shirts to purchase, customers are informed the t-shirts are on backorder until 2119, the projected year for pay equality based on existing data and trends. A separate button lets them donate to NOW.

The "cruel joke" style idea recalls a recent initiative by industry creatives in which bulletproof vests for kids were advertised for sale, leading to a message about gun control, in the wake of the Parkland high school shooting.

"We loved the idea of getting different retailers who aligned with our mission to each put their own spin on the design rather than just creating a single shirt. And the 'backorder' language on the checkout page felt like an unexpected way to drive home our message," comments Matthew Zaifert, creative director, 22squared, in a statement.

See another Equal Pay Day initiative from advocacy group Woman in the Room, which encourages women to send anonymous emails to their bosses demanding pay equity.