PINPOINT DRAFTS AND AIR LEAKS IN HOMES & BUILDINGS. The Regin S220 Smoke Pen generates a thin, dense, white smoke trail perfect for locating the source of drafts and air leaks around windows, doors, outlets, ductwork, exhaust hoods, chimneys, water heaters, attics, eaves, foundations, slabs and sill plates. Great for blower door tests, HVAC balancing, room pressure tests and bump-testing smoke detectors. SMALL, PORATABLE, SAVES YOU TIME & MONEY. Use the S220 Smoke Pen to locate otherwise undetectable air leaks and drafts easily and efficiently during building inspections, home inspections, blower-door tests, California Title 24 inspections, building envelope studies and chimney and fireplace. Use the Regin Smoke Pen to smoke-trail test exhaust fans and hoods, chimneys and flues, furnace exhaust, water heater back draft, laboratory hoods and hospital AFB isolation rooms. DENSE, VIEWABLE SMOKE TRAIL. SAFE, NON-TOXIC, CLEAN, LOW ODOR. No batteries! No messy fluid! Make visual records with camera or video. Light the patented smoke emitting wick with a match or lighter. The glowing tip emits smoke for about 30 minutes per wick. Stop the Smoke Pen by replacing the cap. Relight later. Adjustable wick. Remaining wick stores conveniently in the pen barrel. Not for use near combustible gases. STURDY REUSABLE PEN WITH SIX WICKS FOR A TOTAL 3 HOURS TESTING. REPLACEMENT WICKS AVAILABLE. The smoke stream is dense and white, reacting readily to small drafts and light air movement. The S220 Smoke Pen is a dependable, must-have tool for home inspectors, energy auditors, California Title 24 auditors, building engineers, MRO, plant maintenance, and HVAC professionals. IN THE BOX: One S220 Regin Smoke Pen with 6 refill wicks; Instructions; Additional Refill Wicks sold separately on Amazon. Search: S221 Regin Refill Wicks.