SATCO NUVO's 13 watt T8 LED U-bend tube shaped linear bulb with medium bi pin base is designed to fit into troffers and other fixtures where there is limited space. Comparable to linear bulbs found in offices, healthcare and other commercial spaces, these replacement bulbs are type A/B ballast dependent or ballast bypass. With its high lumen output, and beam spread of 160 degrees, this lamp provides 50,000 hours of natural light.|SATCO NUVO's S18453 13 watt T8 LED U-bend tube shaped linear bulb with medium bi pin base is designed to fit into troffers and other fixtures where there is limited space. Comparable to linear bulbs found in offices, healthcare and other commercial spaces, these replacement bulbs are type A/B ballast dependent or ballast bypass. With its high lumen output, and beam spread of 160 degrees, this lamp provides 50,000 hours of natural light.