Investors interested in Manufacturing - Electronics stocks are likely familiar with Regal Beloit (RBC) and Eaton (ETN). But which of these two stocks presents investors with the better value opportunity right now? Let's take a closer look.We have found that the best way to discover great value opportunities is to pair a strong Zacks Rank with a great grade in the Value category of our Style Scores system. The Zacks Rank is a proven strategy that targets companies with positive earnings estimate revision trends, while our Style Scores work to grade companies based on specific traits.Right now, both Regal Beloit and Eaton are sporting a Zacks Rank of # 2 (Buy). This means that both companies have witnessed positive earnings estimate revisions, so investors should feel comfortable knowing that both of these stocks have an improving earnings outlook. But this is just one piece of the puzzle for value investors.Value investors also try to analyze a wide range of traditional figures and metrics to help determine whether a company is undervalued at its current share price levels.The Value category of the Style Scores system identifies undervalued companies by looking at a number of key metrics. These include the long-favored P/E ratio, P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that help us determine a company's fair value.RBC currently has a forward P/E ratio of 16.20, while ETN has a forward P/E of 23.10. We also note that RBC has a PEG ratio of 1.62. This popular figure is similar to the widely-used P/E ratio, but the PEG ratio also considers a company's expected EPS growth rate. ETN currently has a PEG ratio of 2.10.Another notable valuation metric for RBC is its P/B ratio of 2.15. The P/B is a method of comparing a stock's market value to its book value, which is defined as total assets minus total liabilities. By comparison, ETN has a P/B of 4.06.These are just a few of the metrics contributing to RBC's Value grade of B and ETN's Value grade of C.Both RBC and ETN are impressive stocks with solid earnings outlooks, but based on these valuation figures, we feel that RBC is the superior value option right now. Breakout Biotech Stocks with Triple-Digit Profit Potential The biotech sector is projected to surge beyond $2.4 trillion by 2028 as scientists develop treatments for thousands of diseases. They’re also finding ways to edit the human genome to literally erase our vulnerability to these diseases. Zacks has just released Century of Biology: 7 Biotech Stocks to Buy Right Now to help investors profit from 7 stocks poised for outperformance. Recommendations from previous editions of this report have produced gains of +205%, +258% and +477%. The stocks in this report could perform even better.See these 7 breakthrough stocks now>>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Regal Beloit Corporation (RBC): Free Stock Analysis Report Eaton Corporation, PLC (ETN): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research