It's a lid.
With two sides.
Dual, if you will.
One side fits our XBLOK630 and XBLOK650, and the other fits our XBLOK2235. If you want to keep what's outside your plate from getting inside, this is the thing you need.
Please note that this lid doesn't secure- think of it like an automation compatible dust cover or evaporation limiter, not a hermetic seal.