What's the difference between Type A, B, and C LED tubes?
It's all about the ballast. A Type A tube keeps the existing fluorescent ballast — easiest install, but tied to the ballast's lifespan. A Type B tube bypasses the ballast and wires straight to line voltage — more rewiring, lower long-term cost. A Type C tube runs on a separate remote driver for the best dimming and control.
What is a corn cob LED bulb, and what HID does it replace?
A corn cob lamp is named for its look — rows of LED chips wrapping a cylinder like kernels. It's a high-lumen retrofit for HID fixtures: a corn lamp drops into a wall pack, high bay, or post top to replace metal halide or high-pressure sodium, usually on an E26 or E39 mogul base. Match lumens to the old HID wattage.
PAR, BR, or A — which lamp shape do I need?
The letter is the shape, the number is the size in eighths of an inch. A PAR (parabolic) lamp throws a tight, controlled beam for spotlighting and outdoor floods. A BR (bulged reflector) spreads a softer, wider flood for recessed cans. An A-shape (like A19) gives general, all-around light. A PAR38 is 4.75 inches across.
How do I match the lamp base — E26, E39 mogul, GU10, or candelabra?
The base is the screw or pin that seats in the socket. An E26 (medium) base is the standard household screw. An E39 (mogul) base is the larger screw on HID and high-output lamps. A GU10 is a twist-lock pin base for track and accent lights. An E12 (candelabra) is the small screw for decorative fixtures.
How many watts of LED replace an old incandescent or HID bulb?
Forget watts — match lumens. A 9-to-10-watt LED puts out the ~800 lumens of a 60-watt incandescent; a 15-watt LED equals a 100-watt one. For HID, an 80-watt LED corn lamp replaces a 250-watt metal halide. Read the lumen rating, not the wattage, and check the CCT for warm or daylight color.
Replacing the whole fixture instead of the lamp? Recessed cans are in Recessed Lighting, fluorescent troffers and their LED replacements in LED Troffer Lights, and corn-lamp HID retrofits often pair with full fixtures in LED Wall Pack Lights.
