Measuring 3 foot (900mm) in length this LED tube sleeve is ideal for changing the light output of your light to a Primary Red colour. It is 32mm in diameter which is capable of fitting most types of LED tube (please check your tube for compatibility). The colour output which is noted as primary red is simply a descriptor. The official colour classification of the insert is 106 which can be researched to ensure that it is the particular shade of red required. Due to the products diameter (32mm) it will not fit T12 fluorescent tubes and does not come with end caps. It is important to note that this comes as a clear sleeve with a coloured plastic insert.