The probe is proposed in two sizes at the same cost. The first size is for wafers up to 150mm diameter and the second for wafers up to 200mm diameter.
If small sized wafers are to be measured the smaller version is more suitable for placement of the wafers on the measurement table. The Θ movement clicks in four positions at 90 degrees and the linear movement in up to 10 positions providing repeat placement accuracy of +/- 1mm.