plexiglass proof box top

Hi All,

This is my first post. I have a culinary team building cooking program in NYC and to relax love to bake bread... I also use the breads for my program...my problem is that several years ago I bought a plexiglass proofing box top that fits nicely over a half sheet pan.  I love it. Now that I am a maniac and will bake all weekend long I need more and can't find any. Does anyone know #1 what I am talking about and #2 where to find more?

Many thanks for your help/

Suzi