You can use these Row Counters with circular, double-pointed or straight needles up to size US 10.5 (6.5 mm). It comes in two sizes (Large and Small) in attractive and bright Red & Blue color. It allows you to track row, stitch and pattern counts and slips onto needle, so you can track number of sts. and rows already worked.
Other options from $2.80 to $5.10