They can be used individually

Inside diameter: 9mm

This Losi LOSA3572 pinion gear has 12 teeth cut at 1

RC4WD ZS0731 Chubby 3 Ton Scale Jack Stands Pair

Precision engineered with prototypical details

2 Pair 9" 9443 Carbon Fiber Self-Tightening Propeller Prop DJI Phantom 2 Vision+ Mod 1 Pinion They can be used individuallyGemfan 2 Pairs 9443 Carbon Fiber Propeller self lock for DJI Phantom 2 Vision & Vision+ 9. 4 x 4. 3 9. 4x 4. 3 inch 3K Carbon Propeller Set (Two CW, Two CCW) W self lock nut for DJI Phantom 2, Vision + Size: 9. 4 x 4. 3 inch Weight: 30g (set) Material: 3K Carbon Mounting method: built in lock nut, hand driven installation.