D2 ride height sensors

Hi all, can anyone recommend which ride height sensors to buy please, genuine or pattern?
I see the genuine ones are £90 each but there are lots out there around £25 each. Do the cheaper ones have a reasonable life span or is it a case of you get what you pay for? Any advice greatly received.

I've seen aftermarket which was DOA others with mixed up pinout and as they were considered OK being new and the system didnt work well took hard work to troubleshoot inexistent wiring issues, also i've seen well working ones too, it's a lottery > Genuine is the 100% reliable option but if you find it too expensive buy at least OEM, google out RQH100030G , for example https://www.brit-car.co.uk/product.php/409014/5497/height_sensor_rear_discovery_2___p38_range_rover