Johns Manville's Trymer® 25-50 Polyisocyanurate (PIR) Insulation provides excellent thermal insulation properties and dimensional stability for a wide range of specialized applications. Trymer 25-50 comes in bunstock and can be fabricated into a variety of shapes and sizes. Trymer 25-50 has an ASTM E84 flame spread/smoke developed performance of < 25/50 up to 1.5" thickness which makes it ideal for applications were flammability is critical or governed by codes. It is the only HFC and HCC free PIR insulation to meet 25/50 flame/smoke requirements.