Can anyone recommend a safer marble run for a three year old?

[PTRB]

I have a 3 1/2 year old boy that would love a marble run type toy and keeps asking for one, but the risk of choking terrifies me as he does still put things in his mouth.
Can anyone recommend a marble run type toy please where the balls have holes in them or are bigger and safer etc please?
Thank you

@Nottulip Thank you for your comment.

With many marble runs stating age 3+ i am purely asking if anyone is aware of which might be considered the safest. i.e. maybe some have larger balls which can't be swallowed etc. If this is not something you are able to help with then I thank you for your time in reading my post.

Not sure if you can still buy them but Duplo did a marble run which connected to the blocks with bigger balls.

Many years ago there was also a german company - who made beautiful wooden marble runs am not sure if they made ones with larger balls but maybe worth a google.

The fine motor skills and the level of planning involved in a marble run arent really compatible with the under 3s.
I' d recommend the Fat Brain Toys " Air Toobz"
Its lots of fun, has bigger balls and bigger parts.
Gravitrax Junior is good for when he gets older, the balls are a bit bigger ( but still would be a choking hazard).

@Rocketpants50
Thank you - I will definitely have a look for the duplo one to see if they still do this with the bigger balls, he has tons of duplo so that would be great - thank you

The child is 3.5

@Nittersing
Thank you, i will look those up. He loves building (duplo, car ramps, magnetiles etc.)

We have the connetix marble run that fits with mangatiles if you already have them, the balls are probably around a ping pong ball size!

My three year old also spends lots of time constructing elaborate marble runs with it, not sure why PP thinks 3 year olds can’t!

My son was marble run obsessed - strangely now 16 is rollercoaster mad. There is a great one at the Science museum in London. You could always make your own with kitchen roll tubes! You can also get magnetic ones which stick on fridges - they may have had bigger balls?

Also check out the Quadrilla marble runs for when he can have normal marbles.

Not quite the same but you could try a Brio train set or something like that? The trains are blocky and too big to swallow but can go down slopes and things, and he would still get to set up the track.