No Asian technology company is currently more successful, dominant and more deeply engrained in the daily lives of a billion-plus people worldwide than Largan Precision. While you may not know the name, odds are you carry Largan technology around with you every day.

Largan makes the tiny plastic camera lenses for the high-megapixel cameras built into the iPhone and most higher-end Android devices. Largan enjoys a near-monopoly and is probably the only company in the world supplying an important high-margin component to both Apple (AAPL) and its Android rivals. That means even if Apple’s growth begins to cool, Largan won’t suffer as acutely as other key Apple component suppliers like Silicon Valley favorites Cirrus Logic and InvenSense. Apple may now be more dependent on Largan than Largan is on Apple.

Not that Largan is eager for the world-at-large to know. Though publicly-traded on the Taiwan Stock Exchange, the company is extremely reticent about sharing much information on its robust financial health and its current hammerlock hold on Apple. Largan habitually issues rather gloomy-sounding forecasts, as it did earlier this month, suggesting its growth rate may be slowing. Though its share price has nearly doubled in the last two years, it still trades at an anemic p/e multiple of under 10 times projected 2016 net income.

Smartphone sales are beginning to plateau Also casting a potential shadow, Apple is said to be keen to find an alternative camera lens supplier. The Cupertino company loathes having single-source suppliers like Largan. But, so far it’s proving all but impossible for Apple to find another supplier to match Largan’s price, volume and quality. Patents, Largan has them in abundance. But, its most valuable innovations, the ones Apple and its other customers pay good money for,are mainly unpublished: the sophisticated manufacturing know-how needed to produce in massive quantities at low-cost tiny specs of curved plastic at optical quality.

Fortunes rise and fall quickly in the mobile phone industry. If more proof were needed, just look at Xiaomi, which went from the world’s highest valued to perhaps most overvalued startup in less than a year. Largan, meanwhile, quarter after quarter, remains the envy of the entire Apple and Android manufacturing world.

Cameras — and the quality of photos they take — have never been a more important selling point for mobile handset makers. All the key trends — higher resolution lenses with larger apertures, high-quality cameras front and back, optical zoom and image stabilization — play directly to Largan’s proprietary strengths and know-how.The result, Largan also enjoys about the highest growth rate and market share along with net profit margins among all key mobile component manufacturers.