Sir, – I couldn't believe what I was reading in Ciara O'Brien's column on Tech Tools (October 21st), a toothbrush with a price tag of €650! The review says it is "incredibly smart " and has "artificial intelligence" but I can only ponder what sort of intelligence a potential buyer might have if they are prepared to pay such a hefty price for a toothbrush that you still have have to hold in your hand and move around your teeth to clean them. – Yours, etc, NOEL SHANAGHY, Faithlegg Co Waterford.