They are not compatible, but they can be.
The Toasty Tubes can be easily modified to fit the Zap by threading on a brass roasting tip.
The Zap tubes can be easily modified to fit the Toasty Top by inserting the stainless steel portion of the Toasty Tube into the Zap tube. A silicone band seals between the brass Zap tube and the stainless Toasty Tube.
Lots of flexibility and interchangeability.
Here is a shot gvape provided of the TT in a brass tube tip.
The Toasty Tubes can be easily modified to fit the Zap by threading on a brass roasting tip.
The Zap tubes can be easily modified to fit the Toasty Top by inserting the stainless steel portion of the Toasty Tube into the Zap tube. A silicone band seals between the brass Zap tube and the stainless Toasty Tube.
Lots of flexibility and interchangeability.
Here is a shot gvape provided of the TT in a brass tube tip.