The 3-D Oil Sight Glass is machined from one solid piece of impact resistant, high strength, stain-resistant cast acrylic. It has excellent resistance to hydrocarbon and petroleum-based products, hydraulic fluids, most silicone fluids, and fuels. Replaces problematic, old-fashioned oil level sight plugs. Fits virtually every oil reservoir. Revolutionary easy view design is visible from virtually any angle, minimizing false positives.