This Winter 1 turn Air Speed Indicator (ASI) 7213 fits in to a 57mm panel mount and is rated between 0-100kts. The unit measures 75mm in length and weighs 220g approx.
Although traditionally known to glider pilots who value quality and reliability, Winter ASI's are also suitable for General Aviation (GA) aircraft - in particular homebuilt/kitplane designs and microlights.
Zero is marked at the top of the dial but other presentations are available to order. ASI ranges exist showing airspeed in Kts, MPH and KPH.