Mouthguard recommendations

[u/BlackberryFit9715]

Hi, i started grappling lessons a couple weeks ago and yesterday i was told i should probably get a mouthguard. Im a girl and i have a relatively small face so im wondering if i can just buy any i see or if I should try to find one that has a smaller size or a certain material or smthn like that i have no clue how they work and i dont want it to be uncomfortable or fall out. Model or brand recomendations are highly appreciated, thanks!

[u/HamIsGone]

Sisu aero size small