XXT stylus, 180 degrees. Titanium center fitting with 3.5 mm through hole. Two 2.0 mm diameter Therm-X carbon fiber stems with 3.0 mm diameter ruby balls. Used with a clamping screw or clamping stylus to create a T-shaped probe. Stylus weight is 1.54 grams. Compare to Zeiss 626103-0304-040.