Yes, we supply them pre-assembled and they simply slide over the fluorescent tube and are supported at both ends with the caps supplied. We can also supply them unassembled too. Simply choose a colour and we will send you a Quick Roll of gel 7.62m (25’) long, pre-cut to fit the sleeve size you require. We also supply you with the clear polycarbonate sleeves, cut to your chosen length along with a set of end caps. You then assemble the inserts and sleeves yourself. If you wish to replace or change the colour in an existing sleeve, all you need is a Quick Roll of the new colour. Just let us know what size tube you would like the roll pre-cut to i.e. T5, T8 or T12 tube size.