USA market is full of different types of metal sheet linear high bay. Although the price is cheaper, the fixture is IP20 only, meaning it is not waterproof, nor dust-proof. After 1-2 years usage, the fixture is likely to accumulate dust and damp inside. The insects would follow gap between lens and housing, and the fixture inside would soon have their body, which would decrease lumen output. To be honest, LED is sensitive part, and is better to be fully sealed to prevent LED burnt. Metal sheet LED linear high bay is likely to have LED damage for long time usage.
Below is a pic we took in one of end user warehouse. You could see its surface is already damp.
Why not using waterproof with quality products? We would like to recommend our LHB09 with IP66 and durable structure. See below picture to know more details:
Below is a brief introduction. Please check below. If you have any questions, please feel free to contact us.