We have used this bike for about two years, and my son loves it - sadly he has now grown out of it, but it is a great first or second pedal bike. Very high quality Austrian brand, similar to Islabikes or Frog. It's in good condition with just a few scrapes to the handlebar grips, which can be replaced for £18 if it bothers you.
Very lightweight (5.4 kg). Suitable for a 4-6 year old, with a minimum inside leg of 46cm, max 63 cm (approx 105-125 cm tall)
Review here:
Woom 3 review - a 16" wheel bike for kids aged 4 to 6 years
Pick up from North Dulwich