Linertherm is an insulation for flexible flue liners that you simply wrap and strap around the liner. The advantage is it is quick to put on and easy to install - allowing for some flexing of the liner around bends in the chimney.
Stocked by us, pre-packed and ready to go our Flexline flexible chimney liner comes in two grades. 316 is perfect for most installations, 904 for ones which will be worked hard. A range of easy to use components makes installation simpler and safer so you can then concentrate on sitting relaxing infront of your stove.
Leca is a type of insulation, a little like light pebbles that you pour around the liner. It is good for smaller chimneys - for very large chimneys Linertherm is a better choice.