This is the Mat Room shaders to simulate the glass for the casket.  You can use this for any free coffin you find either in the Rendo freebie section or Sharecg.com; no need to purchase.  This shader arrangement was published by Bagginsbill in a post @ RuntimeDNA quite some time ago, I am not taking any credit for it.  If you search for The Fresnel Effect by BB you should find it fascinating reading.  I don't have the link ATM, only a printed copy.  But I will be glad to shed any further light if you have questions.