This the reason I asked for the link. Just read the specs. .

It tells you what prop to use: 6X3. S

ome of the people who posted their testing are using 5X3 and I would expect a 5X4 would work too.

Dimension: 23mm x 18mm, 31mm(with shaft)
Weight: 12g (kv2900) (not including connectors)
Diameter of shaft:F2mm
Length of front shaft:F8mm
Lamination thickness: .2mm
Magnet type: 45SH

Voltage: 7.4V
Amp: 5.8A
Thrust: 165g
Propeller: 6030