Almost all mid-range fridges with freezer compartment have some type of anti ice buildup function: Low Frost or No Frost. If it does, the compressor has to work less hard, which benefits the lifespan. The shelves are made of safety glass. This allows them to carry a large weight and ensures that they won't break as fast when you drop then while cleaning. The newest mid-range fridges have an inverter compressor rather than a conventional compressor. An inventer motor lasts longer, is silent, and energy-efficient.