Not only is Donald Trump Jr. is a staunch supporter of protecting gun rights, but he is also all for gun silencers, a hot button issue in politics at the moment.
As pointed out by The Daily Dot, Trump Jr. appeared in a (40-minute long) promotional video for SilencerCo, a company that makes gun silencers, which muffle the sounds of gunshots. Silencers are currently strictly regulated in the United States, and the NRA and its supporters are trying to change that.
The video featuring Trump Jr. was released in late September 2016, shortly before the election. In the video, the president's son explains that silencers are great because they make guns more accessible to little kids.