This Scorpion SII-4020 & 4025 Bolt-on Prop Adapter is the same one that is included with SII-4020 & SII-4025 series Scorpion Brushless motors. Machined from High-Quality Aluminum bar stock, it is has a 8mm threaded prop shaft. The Scorpion SII-4020 & 4025 Bolt-on Prop Adapter weights 40 grams.
