Billed as a better way to prevent the spread of sexually transmitted diseases and reduce unwanted pregnancies, an Internet retailer has begun offering a line of condoms that come in 55 different sizes. Los Angeles-based Condomania says the "They-Fit" condoms offer a more comfortable fit than other brands. A better fit should lead to fewer tears and slippage problems and less anxiety, said the company's CEO Adam Glickman. But any correlation between the fit of a condom and how well it protects has not been clearly defined, researchers point out. "We don't have the science to support a need for 55 sizes," said Richard Crosby, an assistant professor at the Rollins School of Public Health at Emory University. Most brand-name condoms, which typically are available in only three or four size variations, can be found in convenience stores or vending machines. But stocking so many sizes will likely keep the "They-Fit" line available only through the Internet or specialty shops, Glickman said.