
Generally you don't see these too often because they are hidden behind a sidecover AND the battery, and they don't do much except blank off the end of the air filter, which fills 99% of the existing space anyway. So when they DO show up (which isn't often, because most threw them away), they command stupid-high prices for the restoration crowd.
I'd always kind of wanted one (for completeness sake), but wasn't willing to pay the $100+ going rate. Thankfully, this one came up for less than a quarter of that, so I snagged it.

Fun fact- there's no fasteners for it. The only thing that holds it on is the battery and the battery holder. But if it works, it works.