Is Echo Circlet legal in Standard, Modern, and Commander?

Echo Circlet is legal in: Modern, Legacy, Vintage, Commander, Pauper.

What type of card is Echo Circlet?

Echo Circlet is an Artifact — Equipment. Its oracle text reads: "Equipped creature can block an additional creature each combat. Equip {1} *After the vanishing of the elder generations, the Anvil Tribe developed creative solutions to their personnel shortages.*"