Outer container
匚 — Kangxi #22, an open-sided box turned on its side. The indexing radical, drawn as the top-left vertical and the closing bottom-right stroke. Anchors
匣 in the container family with
匠 (artisan in a workshop),
区 (zone),
匿 (hide inside). Specifically a small box that snaps shut, like a jewellery case (
盒子).