ROV Propeller adapter : 1/8 Motor to 4mm or 3/16" propellerThis adapter is used to put a propeller directly onto a 1/8" (3.175mm) shaft. This can be used with 4mm or 3/16(4.75mm) smooth bore propellers with drive dog.Specs:Diameter: 13mm Length: 32mm Motor: 1/8" (3.175)Propeller: 4mm or 3/16" (4.75mm)Include:(1) OSE aluminum Rov adapter(1) 4mm x 20mm hex head screw (requires 3mm driver)(2) 4mm grub screws (requires 2mm driver)(1) ose-83400-4316 prop adapter**PROPELLER IN PICTURE #2 NOT INCLUDED**