●Package Content:Pack of 4 black standard size turn on/off switch knobs,lamp switch replacement ●Easy to Install:US standard universal knob,Corrugated knob, non-slip. ●Standard Size: The universal E26 specification is suitable for most desk lamps on the market. ●Application: Suitable for most desk lamps on the market,Replaces old or broken socket keys. ●After-sale Service: If you have any questions with our switches knobs, please feel free to contact or QA us, we will provide you satisfied solutions.