... .single grommet , save cost and manpower steady manual single ring grommet machine Dimension: 150*150*100 mmMould size : standard 4 ... , positive ring and negative ring. To make grommet need install positive ring, and negative ring, then put the flex banner in machine, press ... .Now our single ring grommet machine can solven above problems. It only use positive ring, no need negative ring, save cost; ...