Armor's arNXM vault allows users to stake wNXM tokens with Nexus Mutual without the need to lock their tokens for 90 days. It's been created to boost the amount of capital being staked in the Nexus Mutual protocol. The arNXM Vault accepts deposits of wNXM, exchanges them for arNXM at the current value (based on the amount of NXM the contract has and total supply of arNXM), then a user may withdraw to gain rewards from their staking.