<ul>
<li>Front side - 173mm inner diameter</li>
<li>Rear side - M65x1 male thread</li>
<li>Weight - 403 g</li>
</ul>
<p>This adapter allows using Aerostigmat f/5 305mm (12 inch) lens on focusing helicoids with M65x1 thread.</p>
<p>Made of anodized light alloy.</p>
<p>The adapter is secured on the rear part of attachment with 3 of M5 screws.</p>