It was the perfect time for Dorney Park to add their first looping coaster in 1986. The small, somewhat unknown amusement park located several miles outside of downtown Allentown, Pennsylvania at that time was home to the out and back ThunderHawk 1920s wooden coaster and the more recent Flying Dutchman compact steel twister, among an assortment of flat rides, but needed a major new draw. Dorney was able to get their hands on a double-looping Argentinean steel coaster that Anton Schwarzkopf had constructed four years earlier named Cobra, transported it north and had it rebuilt and running for the 1986 season, to the rapture of United States fans of Schwarzkopf's unmatched intense yet smooth ride experiences. Renamed Colossus, it became the third steel looping coaster in Pennsylvania, but the first to whisk riders through two loops, the previous two coasters being the single-looping SooperDooperLooper at Hersheypark and the shuttle-looping Lazer Loop at Kennywood to the west, both also being crafted by steel looping coaster pioneer Schwarzkopf's company. The Dorney looper sent Pennsylvania thrillseekers through two back-to-back 70-foot loops at over 50 miles an hour, followed by two near-600 degree double helices spiraling upward and downward to form a figure-eight-like layout. Comprised of 2,200 feet of spiny steel track, the nine-story steel coaster features an especially compact track design, being originally designed as a portable attraction to tour fairs. In the 1990s, Colossus received a new name - Laser - along with an adjacent counterpart kiddie coaster dubbed Little Laser, and in 1999 a face lift came with the removal of tacky theming and red and white color scheme, and an eye-catching lime and purple paint job and new logo in its place. Now, over two decades after originally opening, Laser continues to thrill.

But in a different location. The ride was removed to help make room for Possessed, the Intamin Impulse Coaster which was relocated from the now defunct Geauga Lake. Laser was later bought by German showmen Meyer and Rosenzweig. These men owned a fair which they call the Steiger Achterbahn. Laser is now called Teststrecke, or Testtrack in English.

Now Laser’s lot is occupied by the relocated Invertigo from California’s Great America. The ride was repainted to an interesting teal and renamed to Stinger.

Upon being seated in the seven-car train, passengers pull down their individual lap restraints and the ride is dispatched from the station. Laser climbs up a casually-paced lift hill to a peak of 93 feet above the Dorney Park midway, with the looping, swirling tracks about to be ridden lying just out to the right. Once the purple track levels out, it begins to curve to the right, and that curve transforms into a twisting dive sending the train to the bottom of a high-g pullout leading immediately into the first loop. Over four g's of force press against the train as it swiftly navigates the first half of the circular double loops, riders being sent upside down through the top half of the vertical inversion. The first loop is immediately followed up by a second inversion, just slightly shorter but just as intense, in the same direction. Steel track flies by underfoot and the train dives back down to the bottom again to complete the 720 degrees of vertical looping. A banked curve to the left begins, with the train banking and climbing sharply, then diving through the center of the second loop while it circles the spiral of track. After completing the better part of two complete helices, the track threads between the two vertical loops, heading towards the lift hill supports diagonally. Once again, the baking begins, this time in the opposite direction, and riders dive through the second speedy double helix. The train circles around inside the curvature of the first drop, and exits the second helix with a low pass under the track of the first drop. A brake run decelerates the train in front of Laser's twisting layout, and the train curves 90 degrees to the right through a second straightaway before a second 90-degree turn takes the train back into the station, thus ending nearly two minutes of mayhem.