The Explore Scientific 72° ED Series 15mm Waterproof Eyepiece is a deliberate choice for star clusters, nebulae, and broader lunar views. Its 72° apparent field gives your eye useful context around the target, while extra-low-dispersion glass helps preserve contrast and control color fringing.Choose the 15mm focal length with purposeThis is not a generic upgrade. The 15mm focal length is tuned for star clusters, nebulae, and broader lunar views, giving you a clear reason to reach for it when conditions and targets call for that view.Optical details that earn their place 15mm focal length for star clusters, nebulae, and broader lunar views 72° apparent field of view Extra-low-dispersion glass for sharpness, contrast, and more accurate color 1.25-inch barrel with waterproof construction Long eye relief for measured, comfortable viewing Add the 15mm when you want a defined role in your eyepiece case—not another redundant focal length. SKU: EPWP7215ED-01.