Not sure the exact name, but that's a shoebox sized lab breeder cage.
Also called wire-top lab cages.
Tough to find online for a decent price unless you find them used. They show up on EBay occasionally, sometimes for a decent price. I got a bunch of old rusty used ones with tubs, tops and water bottles /sippers for $5 each at my local reptile show.
bigappleherp.com has them in various sizes for about the best new price I have found online, which is still too much per cage in my opinion.
If you want large quantities, try a used dealer like lab4less.com, if you can ever get an actual reply from them. They seem to have hundreds of various types of lab cages on their website.