Robust propeller for glow engines 1.2cc through 2.11cc. Unique scale look for WWI and WWII Model Aircrafts. Available in sizes 16" to 20". Crafted from Glass Fiber Reinforced Composite.Propeller diameter 20" / 508mmPropeller pitch 10" / 254mmStroke thickness 7/8" / 22.2mmShaft diameter 5/16" - 3/8" / 7.94mm - 9.53mm *Propeller Weight 5.86oz / 166.1gDirection of rotation Normal / TractorMaterial Glass Fiber R CompositeColor Black 724446.