Deck Pad for YETI GoBox 30

Our deck pads are made of high quality EVA foam that is easy to clean and UV resistant.   They're installed with a peel and stick backing that will hold up to plenty of abuse without peeling up.  Which size should I buy?   The Gen 1 size will fit any GoBox and is slightly narrower on the long side than the Gen 2.    If you're unsure, the Gen 1 size is the safest choice. How do I know if I have a Gen 1 or Gen 2?  The Gen 1 indention on the top lid is roughly 14.5" wide while the Gen 2 is about 15.5" wide.   The only difference between our two sizes is the width dimension.