Hybrid Catalytic Wood Insert The Regency Cascades i2500 medium hybrid wood burning fireplace insert, featuring Eco-Boost triple burn technology, is designed to fit easily into your existing fireplace, sealing out drafts and offering the perfect amount of heat for most spaces. This catalytic stove offers an increase in burn-times, and most importantly dramatically reduces emissions to an astonishing 1.4 gram/hour. The Regency Cascades i2500 is backed by the industry’s best warranty on both the stove and catalytic combustor.