TheStreet.com Ratings provides exclusive stock, ETF and mutual fund recommendations using proprietary tools. Our "safety first" approach aims to reduce risk while achieving total return performance.BOSTON ( TheStreet) -- The following mid-cap companies have market values between $500 million and $10 billion and received "buy" ratings from our quantitative model, which considers more than 60 factors. The stocks are ordered by their potential to gain. Landauer ( LDR) offers equipment that measures people's exposure to radiation. The numbers: Fiscal second-quarter revenue increased 5% to $25 million as earnings fell 16% to $5.4 million, or 58 cents per share. The operating margin remained steady at 42% and the net margin fell to 22%. The company has no debt. A quick ratio of 1.9 indicates ample liquidity. The stock: Landauer has fallen 8% this year, underperforming the Dow Jones Industrial Average and the S&P 500 Index. The stock offers a 3.1% dividend yield, but trades at an expensive price-to-earnings ratio of 27. Church & Dwight ( CHD) makes household and hygiene products, such as cat litter, cleaning agents and condoms. The numbers: First-quarter revenue rose 5% to $581 million. Net income increased 11% to $63 million and earnings per share, which were hurt by a higher share count, climbed 9% to 88 cents. The operating margin expanded from 17% to 20% and the net margin increased from 10% to 11%. The company has a strong liquidity position, reflected by a quick ratio of 1.1. Its debt-to-equity ratio of 0.6 demonstrates restrained leverage. The stock: Church & Dwight is up 6% this year, beating the Dow, but underperforming the S&P 500. The stock trades at an expensive price-to-earnings ratio of 21 and its dividend yield is less than 1%.