Sure.... go here:

http://www.wichard.com/documents/stainlessSteel.pdf

Scroll down to the 'shackles' page. There's a nice closeup pic of a locking pin. The nice thing about Wichard shackles is that when one opens the shackle, the pin recedes back into the 'slack' (to use Jake's term) side, so there is a full open I.D.

'Spensive? Yeah, but worth it... and if/when you sell the boat, just keep the Wichards if you want to.