How much does this cost to the nearest dollar?

XOAR Aluminum Self-Tightening Propeller Adapter DJI Phantom Self-Tightening Prop on Phantom 4
Allow your Phantom 4 to use Phantom 2 or 3 Self-Tightening Propellers. All hardware included to mount the adapter on Phantom 4. These adapters are color-coded for easy installation Black for CW motor; Silver for CCW motor. Must have for your Phantom 4 to use XOAR DJI Phantom 3 Wood Self-tightening Propellers. MATERIAL XOAR Phantom 4 Aluminum Adapter are Made of Aluminum Alloy Allow your Phantom 4 to use Phantom 2 or 3 Self-Tightening Propellers All hardware included to mount the adapter on Phantom 4 Color coded for easy installation Black for CW motor; Silver for CCW motor Compatible with XO

Price is $17.00
Price: $16.99