Replacement rubber spinner for GWS Electric Power Systems. Press fits over 6" to 12" props onto your 3.0mm diameter drive shaft. 1 per package. All the IPS, EPS100,280,300,370 drive systems have 3mm shafts as do many aftermarket gearbox's for 280-300 class motors as well as most gear drives for 20mm inrunners. This item is 1 spinner, 2 shown in photo for clairity.