Sleep Sacks for twins

Sleep sacks replace loose blankets, and with twins you are buying them in pairs, per size, forever. The real quantity is not two, it is two per size plus spares, because the twin laundry cycle means one is always in the wash. Budget for four to six in rotation once you know what your babies tolerate.

Used is completely fine here. Sacks are worn for weeks per size and the secondhand market is flooded with barely-used ones, often in the exact next size up. Check zippers and washing wear, then buy the lot. Just match the TOG rating to your actual bedroom temperature, not the one in the catalog photo.