always add product Y with product X even multiple

[Ruben-Bike-Butler]

Is it possible to always add a free product with certain other products from prestashop?

 

Case in point: Bike bags with spacers.

 

When a customer orders a BIG bike bag a spacer needs to be added to the cart but when customer buys three bags three spacers need to be added.

 

I got price rules working but that only adds one spacer to the entire order even if several bags are ordered.

The spacer in this case is a free product, but is also sold seperately for other bags that can use them.