10pcs/lot SF2 protective cover is used to protect SHT2x and SHT3x humidity sensors SENSIRION
https://www.vogueparade.com/shopping/EN/150412/1/1005003420053417/10pcslot-sf2-protective-cover-is-used-to-protect-sht2x-and-sht3x-humidity-sensors-sensirion//