Days after Donald Trump was named president-elect, Americans are spreading a message of unity with a simple symbol: a silver safety pin.

The object may seem confusing to many in the U.S., but to those who lived in the United Kingdom during Brexit, it’s a sight they’re very much used to.

In June, millions voted for the U.K. to leave the European union, and to their surprise, they won -- with 52 percent of the vote. But while some celebrated, others were left shocked and afraid the break would cause a divide.

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And they had a reason to be concerned.

In the aftermath of the June 23 vote to leave the European Union, Britain saw a surge in xenophobia expressed in taunts, threats and worse. The hashtag #PostBrexitRacism started trending, as social media users reported verbal harassment on buses, city streets and in cafes.

That’s when the safety pin movement began.

Today... and until people I know and love can feel safe again #safetypin pic.twitter.com/c7jphNYhQf — BeTheChange (@honoraye) November 11, 2016

A Twitter user who helped start the social media campaign said the object would help inspire solidarity and increase safety.

The idea being that anyone against the sort of nationalistic, racist violence we've been seeing could identify themselves as a "safe" ally. — miss pommery 1926 (@cheeahs) June 26, 2016

I quite like the idea of just putting a safety pin, empty of anything else, on your coat. A literal SAFETY pin! — miss pommery 1926 (@cheeahs) June 26, 2016

Months later, Americans are following suit.

Some Muslim women in hijabs have reported harassment and intimidation following the presidential election. Police are also investigating the beating of a man in a Chicago neighborhood by a group who yelled that the victim voted for Donald Trump, CBS Chicago reports.

On Friday, the hashtag #safetypin trended on Twitter, as dozens of people shared selfies with safety pins attached to their clothing.

“Standing together we will be safe,” one user tweeted.

“My #SafetyPin shows I will protect those who feel in danger bc of gender, sexuality, race, disability, religion, etc.,” another said. “You are safe with me.”

I've got safety pins on all my sweaters and jackets, on my husband, by the front door. It's a start. 💔🙏🇺🇸❤️ #safetypin pic.twitter.com/pOPVfLlwyr — Sarah Felsinger (@sarahfelsinger) November 11, 2016

Social media users understand safety pins won’t solely be the item to bring people together after a heated election, but “it’s a start.”