This is an Aqua Craft Grim Racer Precision Metal Prop Balancer.
Three thumb-screw adjusters with Bubble level centered in wide stance base. Balances almost all metal props upto 80mm in size. Made of extruded aluminum.
One prop balancer with instruction sheet, O-ring keepers, .187", 1/8", 3/16" and 1/4" shafts
Length: 6.3" (155mm)
Width: 3" (75mm)
Height: 2.25" (63mm)
Dust mask, Eye protection, Small round file, Small flat file, 220 Wet/Dry sandpaper, Scratch pad (red), Felt tip pen