Sandbox is a housewares item. Source: Nook Miles Redemption. You can't buy it, but it sells for 12,000 Bells. It can also be bought for 2,400 Nook Miles. Happy Home Academy themes: garden and park.
Where to get it
Nook Miles Redemption: Spend Nook Miles at the Nook Stop terminal in Resident Services to redeem this.
