Marble run for DS aged 4...that he can't swallow the balls

[ChristmasCrumpet]

Could anyone please recommend a marble run for a 4yo boy who can't be trusted not to swallow traditional marbles

Something like gravitrax is too advanced, but I'm looking for a happy medium between something with giant playlist sized balls suitable for an 18mth old, and a proper marble run.

Extra bonus if the balls aren't breakable/hard as bullets, as he is a twin and will inevitably pelt one at his sister.

Vtech Marble rush. Balls are still small enough to be put in the mouth but large enough not to be swallowed iyswim.

Oooh thank you, I'll take a look

We just kept the marbles separate and somewhere that ds couldn't find them. We played with it quite a lot but always together

https://www.kidly.co.uk/products/janod/my-first-circuit/24011?colour=multi&utmsource=google&utmmedium=organic&utmcampaign=surfaces&gbraid=0AAAAADfDHQVGR9kRRa9Ha93SM2ues02V3&gclid=CjwKCAjwxaanBhBQEiwA84TVXAMKXohGkfgIc3kB13ds82kJG3URzOL9lnadfMwvNdSDy6ezA3T6RoCPuQQAvD_BwE

This is why the marbles live in a bowl in the top shelf of our kitchen cupboard. DS and DD build the marble run and then with great ceremony, they come to ask for the marbles and we sit with them while they play with it, then put them away again. My two are 5.5 years apart which means that every safety step we put in place for law-abiding DS 10 years ago is still in place for DD who is a rascal, but who accepts these things as if they're law because DS does.

Would connetix work?
We use the balls and hex bugs on ours. My youngest is 3 but developmentally more 6 months old. I don't believe she would be able to swallow the balls. Although it's a supervised toy in our house.

We just picked up a Playtive Junior marble run second hand - think its from Lidl originally. Balls are largeish (larger than marbles) and safe for toddlers - I was delighted because the fear of choking on marbles kept me away from normal marble run! Only thing I would say is that it has to be built in a certain way and it isn't immediately obvious what it is. My 3yo needs some support to build it 'properly', but I imagine will get the hang of it as he gets older.

Another vote for the connectix marble run. Its not cheap but we get lots of play out of the tiles in this house (18month old and 4 year old). The balls are big enough to find if they end up on the floor and neither child has put them in their mouth (yet).

The connectix looks a bit flimsy and like it wouldn't take much for it to fall apart...is this not the case?

The v tech looks more robust?

If but pushed In properly the ball run parts could fall. But the tiles are magnetic. We generally don't experience it falling apart.