老少無欺 [－－无－]

Jyutping lou5 siu3 mou4 hei1
Pinyin lǎo shào wú qī

Definitions (CC-CEDICT)
  1. cheating neither old nor young
  2. treating youngsters and old folk equally scrupulously
  3. Our house offers sincere treatment to all and fair trade to old and young alike.