T shaped or tubular halogen light bulbs are the most common shape for a halogen bulb even though they may not appear to have a perfectly cylindrical shape. These light bulbs are commonly found to have 2 pin bases in a variety of pin widths and pin spacings. These bulbs may also have double-ended bases or have common bases like a medium screw base. Certain manufacturers, typically Japanese and Chinese, use a different part number standardization using the letter J. You may find a JC bulb or JDR bulb that can cross to light bulb with T in the part number.