This is the DuraTrax Ultimate Flywheel Wrench.

FEATURES: Safely and easily holds flywheel of R/C vehicles making tightening and loosening clutch nuts easy. It eliminates the stress to internal engine components Slotted to fit 2-, 3-, or 4-pin flywheels May be stored easily in toolbox or hung on workshop wall

INCLUDES: One DuraTrax Ultimate Flywheel Wrench

SPECS: Length: 5" (127mm)  

BOX DIMENSIONS: 4.00" W. X .38" H. X 6.38" L. BOX WEIGHT: .08 LBS.