This set solves two interesting elements for the marble kit. First it allows longer straights and curves in one piece, and second it allows you to see part of the path through them.

Warning, these are the most delicate pieces of the kit, as they are very thin tubes of filament, and if removed abruptly, they can break. I recommend pushing from the closest part of the piece to where it is hooked.

Marble Kit 4.0 Collection

Marble kit 4.0 Colección por Sergiode21 | Printables.com