The OEM saddle for EQ8 is undersized for attachment of larger/heavier telescopes that use the Losmandy D-rail de-facto mounting standard, resulting in flexure and loss of pointing stiffness. That for the EQ8-R is better proportioned, but again for some payloads it is less stiff than is desirable.
SAE’s HD saddle stiffens the joint with the ‘puck’ on the end of the DEC shaft and supports genuine Losmandy D-rails and close analogues to this profile with wide-based clamps. The substantial thickness of the saddle resists tendency to twist under bending moment loading.
It is also possible to clamp Vixen-style dovetail bars using this saddle. A large hole is provided through the centre of the mounting boss to facilitate both saddle-to-saddle and through-the-mount cabling.