Looking for a specific female Corally tube

[Fiddybux]

Hey all,

What are those 4mm female Corally tubes called where one end is sealed off, but there is just enough room to get a motor wire in and solder it up nice and tidily?

I'm not looking for the tubes that you can see right through (like a bog roll!)...I think the ones I need are slightly longer than 4mm (maybe 6mm) to give you that extra 2mm to put the wire in one end and the other end so it will fit a 4mm banan plug.

It's doing my head in trying to find these. I may even be looking at the wrong type of thing. Maybe I need bullet connectors or something. All the photo's I can find of this stuff is either blurred or doesn't give me enough detail / correct angle of photo.

Can anyone suggest anything specific and tell me where I can get them. Please PM me if this contravenes forum rules.

Thanks.