Mount M Slot

Can someone tell me what this brass barrel with the small slot clearly designed to mate with a PCB mounted nvme drive is called? I guess

Mount M is a slot machine with a prehistoric theme and ancient animals that inhabited our Earth many years ago By opening the Mount M slot, you

mountainbike slot Mount M In a strange twist of fate, players will be transported to the top of a mystical, mammoth-shaped mountain to perform a secret ritual

mount whitney lottery Includes both adjustable accessory slot mount & brim mount; Allows articulation both above and below brim Specifications UPC: 017398806664; Drop Rating: 2 m