Wide Application Range: ideal for laboratory use, accommodating and air-drying test tubes between 0.79 inches to 0.86 inches diameter, as well as centrifuge tubes and other lab vessels Product Features: open-frame design holds more test tubes and lets you store cleaned tubes for drying; practical and easy to use Durable Material: constructed from 201 stainless steel, ensuring a solid build, long-lasting durability, and resistance to both acidic and alkaline environments Stable Triple-Layer Design: features a 3-layer design that effectively prevents test tubes from shaking, minimizing the risk of damage