PARK TOOL Chainring Wrench CNW-2
The CNW-2 makes mounting and removing chainring bolts child's play. With it, the slotted nut is securely fixed while you turn on or unscrew the chainring screw. It can be used on both sides and therefore fits most slotted nuts.
Material tool: stainless steel
Scope of supply: 1x PARK TOOL Chainring Wrench CNW-2
Further hints for the use can be found here .