Ernie
Go to this web site. <A target="_blank" HREF=http://www.ag1.net/catalog/>http://www.ag1.net/catalog/</A> and go to the 3pt tools section and click on clamps.
My two new clamps are C5821, which I recomend as easier to adjust and use. My older clamps are similiar to C5820 with two square bolts used to tighten the shank as opposed to one large hex bolt on the C5821. The C5821 are also easier to adjust to the 2-1/2 toolbar./w3tcompact/icons/cool.gif
Mike