Colin Kaepernick may still be unsigned, but his fans are making sure they show support to him off the field.

Kaepernick’s Air Force 1 collaboration with Nike is no longer available online. According to Nike’s website, the shoes sold out in all kids and adult sizes in just minutes. “This Air Force 1 season, Nike partnered with a collective of collaborators to design an AF1 that connects to their life personally. Colin was identified because we believe his voice and perspective inspire many generations on and off the field,” Nike said in a statement.

The collaboration comes just over a year after Nike released an ad campaign with Kaepernick. Many customers called for a boycott of Nike over their collaboration, but the Nike shares actually surged 36%. The run-up included a nearly 5% increase since Nike’s announcement of the campaign on Labor Day 2018, which added nearly $6 billion to the company’s market value. The ad even went on to win an Emmy for Outstanding Commercial.

Kaepernick is also helping Nike fight against injustice. According to CBS News, “During the summer, Nike decided not to release its Air Max 1 Quick Strike Fourth of July shoe, reportedly because of objections from Kaepernick, who told the company that the Revolutionary-era U.S. flag with 13 white stars and a circle heralded back to a time when black people were enslaved and that it has been appropriated as a contemporary symbol by white nationalist groups.”

Kaepernick is still fighting to be able to play on an NFL team. He was recently invited to a private workout by the NFL, but things didn’t turn out as planned. Kaepernick reportedly changed the workout location to accommodate the media and spectators. He also refused to sign a liability waiver that the NFL had introduced to him earlier that day.

Following his departure from the 49ers in 2016, Kaepernick stayed unsigned through the off-season and during 2017. Many believe the football player had been blackballed over his advocacy for the Black Lives Matter movement, which he demonstrated by kneeling during the National Anthem.

Kaepernick sued the NFL, accusing owners of colluding against him to keep him out of the league. In February, it was announced that Kaepernick reached a confidential settlement with the NFL.