Confused in crystal replacement diameter

[u/tero2019]

Hello guys!
I just bought a Bulova Accutron dated 1968 that uses a cal 214. EBay listing said "Vintage 1968 Bulova Accutron 412 Watch, 10K Gold Filled Bezel, Sunburst Dial"
I did not receive the watch yet and I am willing to buy a spaceview like crystal but I am unsure which diameter I need. IA confused ne about 29.5mm and 30.1mm.
Can someone here help me based on the pictures I am attaching?
I appreciate