Building a trap is not out of the question, and some older books on vacuum may have tips on fabricating your own.
It is basically a fine wire basket in a metal can with input and ouput vacuum lines. A bakeout heater should be supplied within the basket that holds the zeolite compound.
These are called molecular seive traps.
Richard Hull
Created on Thursday, February 22, 2001 4:46 PM EDT by Richard Hull