Vermont will outlaw bump stocks exactly one year after the mass shooting at a Las Vegas country music festival, where the devices were found on 12 of the gunman's rifles.

The tragedy prompted a bipartisan outcry in Washington, D.C., as national leaders called for limits on bump stocks. President Donald Trump and Attorney General Jeff Sessions proposed a rule change at the Bureau of Alcohol, Tobacco, Firearms, and Explosives that would ban bump stocks by classifying them as "machine guns."

At least nine states, including Vermont, have outlawed bump stocks. Vermont's law differs from several other states in that it does not provide any payment for people who must relinquish a bump stock.

More:Gov. Scott signs Vermont gun bills: When new steps take effect

Gun-rights activists are challenging the new law in Vermont Superior Court.

Here's what you need to know about bump stocks in Vermont:

What is a bump stock?

A bump stock, or bump-fire stock, is a device that allows a semiautomatic gun to fire more quickly by taking advantage of a gun's recoil motion. The motion of the gun activates the trigger at a rate that mimics a fully automatic weapon.

Bump stocks are considered a novelty device because they decrease the shooter's accuracy. "They're a gimmick or a toy," said Sen. John Rodgers, D-Essex/Orleans, when the Senate was debating the bump stock ban earlier this year.

The devices can cost more than $100. The state of Washington values each bump stock at $150 in its buyback program, while Delaware offers $100 per bump stock.

Vermont lawmakers banned bump stocks as part of a package of gun regulations that passed after police arrested an 18-year-old suspected of planning a school shooting in Fair Haven. Gov. Phil Scott signed the ban into law on April 11, and it takes effect Oct. 1.

Can I keep a bump stock I already own?

No. When the state passed a ban on certain sizes of gun magazines, lawmakers included a "grandfather" provision that allowed Vermonters to keep magazines they owned before the law took effect. There is no equivalent loophole in the bump stock ban. After Oct. 1, it is illegal to possess a bump stock in Vermont.

What are the penalties for having a bump stock?

Possession of a bump stock is a misdemeanor under the new law. When the law takes effect Oct. 1, anyone convicted of having a bump stock in Vermont can face up one year in prison and a $1,000 fine.

What am I supposed to do with a bump stock that I own?

The new law requires the Vermont Department of Public Safety to collect bump stocks from Vermonters in anticipation of the ban. The state is inviting Vermonters to relinquish their bump stocks anonymously, without compensation, at any of the 10 Vermont State Police barracks. The barracks are open from 8 a.m. to 4 p.m. on weekdays.

People must remove the bump stocks from their weapons before entering the state police barracks. The devices will be made inoperable and disposed, said Capt. Timothy Clouatre.

Clouatre said the Vermont State Police has no estimate of how many bump stocks exist in Vermont.

How have gun-rights activists responded to the ban?

Gun Owners of Vermont, an organization that advances a no-compromise approach to gun rights, filed a lawsuit in August against the bump stock ban.

The group is asking the court to declare the ban unconstitutional because, they argue, it violates the right to bear arms in the Vermont Constitution.

Meanwhile, Gun Owners of Vermont President Eddie Cutler suggested in a public Facebook post that people who own bump stocks should give them to a friend outside Vermont "till we win the court case."

Clouatre, the designated media contact regarding bump stock collection at the Vermont State Police, said he had no comment as to whether this approach was an appropriate alternative to surrendering the devices.

Contact April McCullum at 802-660-1863 or amccullum@freepressmedia.com. Follow her on Twitter at @April_McCullum.