Many fire alarm pull stations are single action and only require the user to pull down the handle. Other fire alarm pull stations are dual-action, and as such require the user to perform a second task before pulling down, such as lifting up or pushing in a panel on the station, or shattering a glass panel. The Fire-Lite BG-10 and the Cerberus Pyrotronics (Siemens) MS-501 are examples of this design. Perhaps the most recognizable pull station is the T-bar style pull. The style is so named because the handle is shaped like the letter "T". This style was first manufactured by Simplex, and is now manufactured by many other companies.