The $1K deposit cap hurts this deal. If you choose the 12-month term, you'll earn $50 over what you would earn in a 5% account which isn't too bad. There'll be less of a gain for the shorter terms. I can't find other details of this special CD on the website. You may be able to open one per family member rather than one per household. That can also help improve this deal.
Membership is open to those who live, work or attend school in Middlesex or Suffolk County, or in one of several Massachusetts cities. Membership is also open to MA residents of Portuguese descent. Please see the credit union's eligibility page for the full details. Membership requires a minimum deposit of $25 into your savings account.
Branches are located in Somerville and Cambridge, MA. The credit union is federally insured by the NCUA (Charter # 68046). It has $77.5 million in assets and 23,705 members.