Gotcha!<a href=showthread.php?s=&postid=7204869#post7204869 target=_blank>Originally posted</a> by B.PETERSEN
On the inside envelope, near the edges, where the wires go into the envelope. All three of mine are just clear glass...
Just looked at one of my XMs...my XM SE 250 10K has white sides (no number stamped on it) while my Reeflux SE 250 10K is completely clear with the number 510 stamped on it.