Square Plug Gauge Go- 7.503 to 7.505 / 7.503 to 7.505 & Nogo- 7.648 to 7.650 / 3 to 5 mm, Go Length- 29.00 to 31.00 mm, Nogo Length -10.00 to 11.00 mm (Required checked the Inside Profile of Square slot with Go Nogo Gauge for Square Slot.(H0103.0102 )