Our client regularly orders these 4 page DL and 6 page DL brochures.
Printed on 150gsm gloss art.
4 page flat size is 198 x 210mm, folds to 99 x 210mm
6 page flat size is 297 x 210mm (A4), folds to 99 x 210mm.
Trick with 6 page DL brochures is to make the panels 99mm, 99mm and 97mm to allow the last page to tuck in nicely.