Six men have been jailed over a £17m fraud involving selling solar panels to elderly, retired and vulnerable people.
The 1,500 victims were "manipulated" to buy panels with the promise they would get their money back from investments, the Serious Fraud Office said.
But the jury heard the gang spent the cash on sports cars and holidays.
Ludovic Black, David Diaz, Robert Ross, Kenneth Reid, Stephen Wilson and Niall Hastie were jailed following a trial at Liverpool Crown Court.
The men ran a company called Solar Energy Savings Ltd, based in Manchester, which is no longer trading.
The court heard the victims were promised the cost of the panel installations would be invested and they would get their money back in five years, but as it was never invested, the money was not returned.
The Serious Fraud Office (SFO) said the victims had been "manipulated" by "deceitful sales techniques, outright lies, and false guarantees of reimbursement" which ultimately led to victims losing between £10,000 and £20,000 each.
Ringleaders David Diaz and Ludovic Black, two brothers from Glasgow, were caught during a routine police traffic stop in Cheshire, after 11 months on the run and went on trial in April.
Prosecuting Alastair Webster QC said the fraudsters used a "fake and cynical brochure which told a series of lies".
He said they were "wholly uncaring about the impact on their customers".
Lisa Osofsky, director of the SFO said: "These men built predatory schemes to steal thousands from the hard-earned savings of vulnerable people while pretending to offer them a chance to improve their own financial security."
- Ludovic Black, 38, was jailed for seven years and eight months for fraud
- His brother David Diaz, 34, was sentenced to six years and eight months for fraud
- Robert Orr Ross, 52, from Ayr and Stephen Wilson, 56, from Widnes, Cheshire received sentences of four-and-a-half years
- Kenneth John Reid, 60, and Niall Hastie, 54, from Glasgow were both jailed for three-and-a-half years