These are generic acrylic glasses (NOT made by Omega) with date window.
The size is 29.6mm outer base diameter - a very common size for 1960s Seamaster/Geneve type watches (PZ5118 and PX5118 crystal codes). Please check before ordering or send me your case number and I will check for you. There are other sizes available for these glasses as some of the 1960s Seamasters were smaller or larger.
Glass height is about 5mm.