This items is:
A heat press teflon sheets that is non-stick, high-temperature resistant, and features a PTFE protector. 
Select either 2x (38cm x 38cm) or 2x (40cm x 50cm), depending on your requirements.
The benefits of using Teflon sheets in heat press applications
Teflon sheets protect fabrics from direct contact with the heat press, reducing the risk of scorching, burning, or leaving unwanted heat marks.
Teflon has a non-stick surface, which prevents heat transfer vinyl (HTV), ink, or other transfer materials from sticking to the heat press platen.
They can withstand high temperatures (up to 500°F or 250°C), which makes them ideal for repeated heat press applications.
The non-stick property of Teflon also makes it easy to clean, clean with a damp cloth. 
Teflon sheets help prevent moisture from disrupting the heat transfer process, which is particularly important when working with delicate materials.