Xtratherm RLOC2 Pitched Roof Insulation has a unique width variation feature offering a 10-20mm adjustment margin to ensure a tight fitting, high performance insulation locked between rafters. Used in conjunction with a layer of Xtratherm XT/TL or XT/PR below the rafters, the Rafterloc system provides a robust, cost effective solution to insulating sloped rafters to the most efficient standards with minimal wastage and reduced fitting time.