Investors with an interest in Medical - Products stocks have likely encountered both Envista (NVST) and Boston Scientific (BSX). But which of these two stocks is more attractive to value investors? We'll need to take a closer look to find out.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 favors stocks with strong earnings estimate revision trends, and our Style Scores highlight companies with specific traits.Currently, Envista has a Zacks Rank of #2 (Buy), while Boston Scientific has a Zacks Rank of #3 (Hold). This means that NVST's earnings estimate revision activity has been more impressive, so investors should feel comfortable with its improving analyst outlook. But this is only part of the picture 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 Style Score Value grade factors in a variety of key fundamental metrics, including the popular P/E ratio, P/S ratio, earnings yield, cash flow per share, and a number of other key stats that are commonly used by value investors.NVST currently has a forward P/E ratio of 22.19, while BSX has a forward P/E of 26.33. We also note that NVST has a PEG ratio of 0.84. This popular metric is similar to the widely-known P/E ratio, with the difference being that the PEG ratio also takes into account the company's expected earnings growth rate. BSX currently has a PEG ratio of 2.82.Another notable valuation metric for NVST is its P/B ratio of 1.77. 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, BSX has a P/B of 3.76.These are just a few of the metrics contributing to NVST's Value grade of B and BSX's Value grade of C.NVST stands above BSX thanks to its solid earnings outlook, and based on these valuation figures, we also feel that NVST is the superior value option right 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 Envista Holdings Corporation (NVST): Free Stock Analysis Report Boston Scientific Corporation (BSX): Free Stock Analysis Report To read this article on Zacks.com click here.