@Stitchface The Mini AV Meiki series is pretty fantastic. Smaller, very well priced and most of them feel great. My top pick is the Mina Kitano. Really packs a punch for such a small ona.

Also the Japanese Real Holes are fairly goof for smaller onas- though not quite as small as the AV Minis. Japanese Real Hole Raw Saika Kawakita is excellent.

@Stitchface 
I been digging the tomax brand. Amazing for smaller size guys.
I have the Venus real and lilith soft.
Its great suction and the durability last a long time, highly recommend.

I still wish to find the perfect fit for someone who is 4" too, its a journey of trial and error

@Stitchface puni virgin mini is fantastic. It's firm enough to be tight and stimulating and feels rich as opposed to rubbery. As far as small onaholes go I think it's gotta be one of the best.

@Stitchface Also what is useful is if you view all sleeves in the shop there is a filter on the left for tunnel length. From there you can further filter based on your preferences. I've also been on the lookout for shorter ones as well for easier cleaning. I've been debating to go single layer for easier cleaning as well.

@Stitchface 
Goku-Tsubu Virgin and Goku-Hida Virgin Octopus are both very nice with ~4" tunnels. Absorption Lamia Six Ball is also pretty sweet as a lower-priced option with ~4.5". These are all parts of series that all follow the same size standards so you can shop around for a specific interior you think looks cool.

@Stitchface
My all time fav is Erena-Extra.
It's 4.25" tunnel length, but squishes enough such that you can push down to reach the end.

The AV Mini Meki series that has already been mentioned is a great option.
I personally loved the 2022 models, disliked the 2023 models (too stiff/rubbery inside), and just ordered 2024 model to try out