During a demo for the new Tesla "Cybertruck", Elon Musk had an embarrassing moment when demonstrating how hard the windows were to break. 

Twice, the truck's windows were smashed, with Mr Musk joking there was "room for improvement". 

The all-electric truck was unveiled in Hawthorne, California, where its stainless steel, angular design was greeted with cheers but also bemusement. 

Tesla's truck will be sold starting at $39,900 (£30,900),for a model which has a range of 250 miles (402km), while the most expensive model, at $69,900, will have a range of 500 miles. 

It will seat up to six adults and haul a payload of 3,500lbs, Tesla said. 

Full story:Tesla's new Cybertruck smashed during demo