<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div id="yui_3_16_0_1_1443821559549_2401">Hi Sean,</div><div id="yui_3_16_0_1_1443821559549_2401" dir="ltr">My wife fixed things so my Mac could run your head calculator on Psubs. My question is with the elliptical head inside depth, measure at the tangent line. Where is the tangent line, I am assuming from the base of the knuckle? </div><div id="yui_3_16_0_1_1443821559549_2401" dir="ltr">Hank</div></div></body></html>