Many models provide adjustable, multi-level volume controls (examples list up to 32 steps). Some manufacturers publish a maximum loudness — one model is listed at about 90 dB — while others describe relative levels such as low/medium/high or ascending volume.
Common materials include various plastics (including ABS — acrylonitrile butadiene styrene) and, for some mechanical or vintage-style models, metal components.
Options range from classic, loud buzzer tones to multiple selectable wake sounds and natural sleep/wake sounds (white, brown, or pink noise). Many units also offer features such as ascending volume and selectable high/low alarm levels.
Displays are usually LED or LCD. Several models offer on-demand or short-duration backlights (for example, 5–10 seconds) and some let you adjust display brightness across multiple levels.
Common extras include sleep or white-noise sounds, multi-color night lights with adjustable brightness, multiple wake sounds and adjustable volumes, snooze functions, and on some digital units, calendar or temperature displays.
