I purchased 100mm x 2 and 140mm x 2 sheep wool insulation I have found that my room in the roof is warmer and also less noise from the busy road outside. As mentioned by other there is a slight "farm " smell to the product however as it is in the loft it does not matter. No messing around like with glasswool and having to gear up to use it. my rolls went farther than expected so now have enough to insulate an " outside " room that was not insulated when built This review is from central belt Scotland where it gets quite cold in winter. I would recommend this product