A T8 led tube is the most common lighting fixture in residential and office areas where they are commonly  used in high bay fixtures, troffers, and other general lighting applications.

T8 led tube got its name from the diameter of the tube used in this fixture. 

Most fluorescent tubes are called T8 tubes but the sizes vary according to diameter so we have T5,T8 and T12 tubes commonly available. 

T8 led tubes are far more efficient and sustainable than simple T8 tubes; they even have longer life spans. And work best in temperature controlled areas. LED tubes offer better color rendering, require less maintenance, and burn out less frequently with up to 100,000 lifetime hours.

LED tubes can be retrofitted in place of fluorescent fixtures where you just swap the fluorescent tube light with led tube light.  

Retrofitting an existing fixture is not as hard and mostly can be done without any technical assistance as long as you know if your selected tube is compatible with the fixture. 

Initially a led tube light was designed to be direct wired which only had one wired end and used non shunted ballast while the other end was used as support mostly. As time progressed double ended  led tubes have been manufactured to support non shunted or shunted end.

These lights are usually classified as UL Type A, UL Type B or UL type C light. 

UL type C being plug and play is ballast compatible and requires no extra effort.

While UL Type A and B has certain specifications as:

UL Type A: 

is ballast compatible and it has an integrated LED driver which is compatible with T8,T5 and T12 fixtures. It’s the easiest to install and only requires before hand ballast compatibility to be checked. 

UL type B:

Also known as ballast bypass led tube. UL type B’s have an Internal driver which is powered directly from mains supply thus bypassing any ballast compatibility issues. It helps cut down extra maintenance cost and is quite efficient with reduced power loss as it is directly connected to voltage supply.   You might need technical assistance while installing. 

UL Type C: 

Ul type C is remote operated and the most enhanced version of retrofit led tube lights. It does require fixture modification but instead of being connected to mains supply it is connected to sockets and does not work on existing ballasts. So the bigger advantage is that one LED driver can power several led tubes cutting down on cost and separate driver requirements. Which makes UL type C the most efficient type of retrofit led tube. 

Hybrid LED tube 

Use either of the type A or Type B installation method and they have the ability to operate off the existing fluorescent ballast and also have the ability to operate off of line voltage. So if the ballast gives up it still runs on line voltage.

Uses of LED tubes: 

Led tubes are quite an efficient innovation in led technology which have entirely replaced fluorescent fixtures given they have a longer life span and are brighter than any of the traditional bulb sources.

Their brightness is measured in lumens unlike traditional bulbs whose efficiency is checked through wattage rating e.g a 100W incandescent bulb is less brighter than 100W led tube. 

LEDs offer correlated colour temperature and CRI rating above than 80 which means they are available in various ranges of colours in adjustable colour temperature measured in kelvins(K). 

This  makes them a good replacement option in offices, residential areas, warehouses and basically in those fixtures where previously fluorescent tubes were used.  

Additionally, T8 led tubes can replace T12 fluorescent fixtures also which were used in high bay and troffer lighting fixtures in large ceiling spaces. 

LED tube lights have marked an important innovation in lighting technology ever since they were introduced being so convenient and efficient in all aspects of their functionality.