An unknown number of guns are being built with the mechanisms, causing problems for the police and ATF officials. Photo: An ATF agent holds a generic unfinished receiver, back, and one that has been manufactured, front, at an ATF field office in Washington, on May 06, 2014. The ATF is trying to crack down on the trade in the makeshift guns by targeting shops and individuals who offer to turn the unfinished receivers into functional pieces for firearms. (Photo by Bill O'Leary/The Washington Post)

Vivid Sydney is a unique annual event of light, music and ideas, featuring an outdoor 'gallery' of extraordinary lighting sculptures, a cutting-edge contemporary music program, some of the world's most important creative industry forums and, of course, the spectacular illumination of the Sydney Opera House sails. It positions Sydney as the creative hub of Australia and the Asia-Pacific region, and delivers both innovative live entertainment and creative inspiration on a grand scale.

A model backstagee is pictured before the Philipp Plein Spring/Summer 2016 collection during Milan Fashion Week in Italy September 23, 2015. (Photo by Alessandro Garofalo/Reuters)

Sister Rebecca Leis pours low-gluten alter bread batter into a machine that bakes the thin bread at the Benedictine Sisters of Perpetual Adoration monastery in Clyde, Missouri, December 18, 2014. The Sisters have made communion wafers since 1910 and began making a low-gluten version in 2003 and have gone from 143 customers in 2004 to more than 11,000 customers from around the world. (Photo by Dave Kaup/Reuters)

A motorist holds on to a post as she braves high winds and rain of Super Typhoon Meranti in Kaohsiung, southern Taiwan, 14 September 2016. The storm is the strongest recorded since Super Typhoon Haiyan developed in 2013. (Photo by Ritchie B. Tongo/EPA)

People stand in the middle of the graves and in front of giant kites in the cemetery of Santiago Sacatepequez, Guatemala, November 1, 2015. Dating back 116 years, the tradition of flying kites in the cemetery of of Santiago Sacatepequez, integrates the Catholic feast of All Saints with ancient Mayan practices of honouring the dead. It is believed that the kites connect the living and the dead during the all saints day celebration. (Photo by Jorge Dan Lopez/Reuters)

Rich Paul, Simon, Tristan Thompson, Khloe Kardashian, Lucas Newton, Kendall Jenner, Justine Skye, Jordan Woods and Kylie Jenner pose for a photo as Remy Martin celebrates Tristan Thompson's Birthday at Beauty in Los Angeles on March 1, 2018. (Photo by Jerritt ClarkJerritt Clark/Getty Images for Remy Martin)

Wasibi, (r), yawns at backstage before the Algonquin Hotel’s Annual Cat Fashion Show in the Manhattan borough of New York City, New York, U.S., August 1, 2019. The theme of this year's show was “It's a Small World”. The cats represented countries including Ireland, Spain, the United Kingdom and the United States. (Photo by Jeenah Moon/Reuters)