This item is currently out of stock.
A livewell or baitwell drain that won't seal costs you water, and if you're keeping bait or a catch alive, that matters. This rubber plug from Whitecap seats into a 3/8-inch drain fitting and holds a tight seal until you're ready to let the water out.
It's a small, inexpensive part, so it's worth keeping a spare in your gear bag in case the original goes missing or wears out.
Keep one on hand, it's a tiny part, but losing it means losing your seal.