QNAP adapters for M.2, U.2 and E1.S drives. Sorted by how many NAS models each is listed for.

PartNAS modelsBuy
QNAP QDA-A2AR121Amazon eBay
QNAP QDA-A2MAR118Amazon eBay
QNAP QDA-UMP47Amazon eBay
QNAP QDA-SA-4PCS5Amazon
QNAP QDA-SA2-4PCS4Search Amazon
QNAP QDA-U2MP4Amazon eBay
QNAP QDA-E1SM22Amazon eBay
QNAP QDA-UMP2Amazon
QNAP QDA-UMP4A2Amazon eBay
QNAP QDA-E1SM1Search Amazon