Nuclear magnetic resonance (NMR) is considered one of the “big guns” of the analytical instrument industry, with annual sales rapidly approaching the $1 billion mark. While one may be impressed by the sheer size of NMR systems with high-strength magnets, the probe, which provides the means to interface the sample with the instrument, is an important—if small in size—contributor to the performance of an NMR system. The continued development and improvement of NMR probes has helped to increase the usefulness of NMR across a wide variety of applications, which is in turn helping to drive strong growth for not only NMR probes, but the entire NMR market. For a long time, NMR system vendors offered a limited line of general-purpose NMR probes. More advanced and specialized NMR probes were custom built by specialists and researchers. However, over the past two decades, the development of commercial versions of these customized NMR probes by both system manufacturers and smaller, more specialized vendors has resulted in a broad array of NMR probes that provide improved sensitivity. These probe developments have allowed end-users to address the sensitivity limits of NMR, which have traditionally been overcome only with expensive high-field magnets. Cryogenic NMR probes cool the sample to very lower temperatures, which decreases analysis time. Capillary and micro NMR probes are useful in cases where sample amounts are very limited, and would otherwise have mass concentration–related sensitivity issues. Advanced solid-state NMR probes such as MAS (magic angle spinning) are a hybrid of probes used for liquid samples and those used for solid samples, and are useful for tissue analysis. Suppliers also offer more customized probes for specific applications. While the other major components of an NMR system can last a decade or longer, NMR probes typically last only several years. Because the probe has moving parts, is exposed to samples and can be switched out of the NMR system, they degrade much more quickly and are more subject to damage. In addition, the technological development of NMR probes has far outpaced that of NMR electronics or magnets, leading to multiple generations of probes being purchased over the lifetime of a single system. The price of a single NMR probe is not insignificant, as most can cost between $30,000 and $100,000. The need to replace older, outdated and less-sensitive NMR probes, as well as, to a lesser extent, the need for specialized probes for niche applications, has led to an aftermarket demand of close to $60 million. This accounts for more than a third of the aftermarket demand for NMR, and is expected to generate 12%–15% annual growth over the next several years.