A 17-year-old from Surrey is facing charges after trying to sell brass knuckles at various stops along the SkyTrain route, Transit Police say.

Transit Police followed up on a tip that "a youth was advertising fully functional brass knuckles for sale on Craigslist and selling them at points along the SkyTrain route in Surrey", said spokesperson Anne Drennan in a statement.

Undercover officers caught the teen selling three sets of brass knuckles, which are listed as prohibited weapons under the Criminal Code.

A fourth set of knuckles was found at his residence, Drennan said.

Police say the teen is well known to police. He is due to appear in court on Wednesday.