Key-Id's FIDO U2F token is a (very) small conveniently sized 2nd factor token, supporting FIDO U2F for 2FA/SSV on various sites. I find it a useful accompaniement to my Yubikey
In order to be able to use it with U2F on Linux though, you'll probably need to add a udev rule so that the device is correctly detected. This documentation details the rule to use.
For reference, this is the detail provided for these dongles by lsusb
Bus 001 Device 031: ID 096e:0850 Feitian Technologies, Inc. Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 1.10 bDeviceClass 0 (Defined at Interface level) bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 64 idVendor 0x096e Feitian Technologies, Inc. idProduct 0x0850 bcdDevice 53.01 iManufacturer 1 FS iProduct 2 ePass FIDO iSerial 0 bNumConfigurations 1
# /etc/udev/rules.d/70-keyidu2f.rules
ACTION!="add|change", GOTO="u2f_end"
# Key-ID FIDO U2F
KERNEL=="hidraw*", SUBSYSTEM=="hidraw", ATTRS{idVendor}=="096e", ATTRS{idProduct}=="0850|0880", TAG+="uaccess"
LABEL="u2f_end"