Drain plugs have a tendency to walk off sometimes. Fortunately, replacement drain plugs are available from Bison Coolers. All drain plugs are available in 2-Packs so you can always have a spare.
Bison Drain Plugs (GEN1) are direct replacements for GEN1 Coolers only. These were manufactured between 2012 and 2017. If your drain plugs don't look like these, then you should reference the GEN2 Bison Drain Plugs.