New high output chimney is 3" taller than a standard chimney. The increased height means more oxygen is drawn over the flame, resulting in up to 20% more light. Aladdin's exclusive borosilicate glass is shatter resistant and can withstand immense heat. All chimneys carefully inspected and are free of bubbles and other defects. It's the finest lamp chimney available! 15-1/2"H, 2-5/8" OD base. IMPORTANT: High Output Chimney is required at altitudes above 4,000 ft. Note: Logo on chimney is white.and the new MAXbrite logo (not as pictured). Note: Measurements are approximate and can vary slightly. Find the Right Fit! Heel-less Chimney: Fits lamps made in the first half of the 20th century (Models 3, 4, 5, 6, 7, 8, 9, 10, 11) and from 2000 to 2015 (Model 23a). "Lox-On" Chimney: Fits lamps made between 1932 and 1983, models 12, 21, 21c, 23, A, B, C). MAXbrite Chimney: Fits all models except 12, 21, 21c, 23, A, B, C).