Colin Kaepernick's new football jersey might not have an NFL team's name on it, but it certainly carries a message.

Kaepernick on Monday tweeted a picture of the jersey, which is available for pre-sale on his website. Later in the day, Kaepernick tweeted an update that the jerseys were sold out. The jersey is all black with white letters and numbers and features "#IMWITHKAP" embroidered across the front. Kaepernick remains a free agent after last playing in the NFL in 2016.

No. 7, which Kaepernick wore during his six seasons with the San Francisco 49ers, is also printed on the jersey, along with his name. As Kaepernick tweeted, 20 percent of the proceeds from jersey sales will go to his Know Your Rights foundation, which was designed to "raise awareness on self-empowerment and interacting with law enforcement."

The limited-edition jerseys come in youth and adult sizes and sell for $99.99 and $174.99, respectively. The jersey release comes just days after Nike unveiled Kaepernick as the face of its new advertisement campaign.

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