Baader Standard Base, For MQR III&IV, Witty I &V-Bracket
Standard Base for MQR III & MQR IV, for Witty I & for V-Bracket #2457010 from Baader Planetarium
There is one central hole on it for a sink-head screw with hole diameter 6.30mm
The other two alongated holes will allow securing it with two screws to a telescope.
The two screws can be at distances between 25mm to 45mm, center-to-center, approximately.
The uncertainty of measurement comes from the fact that the bottom of the base is curved.
The 25mm to 45mm are center to center of two imaginary screws, as the actual distances are 21mm to 50mm.