Wiki which claims that there is binary release for Mk II is lying. You have to compile your own.

https://github.com/inversepath/usbarmory-debian-base_image

dpavlin@klin:~/usb-armory/usbarmory-debian-base_image$ ls -al usbarmory-mark-two-debian_stretch-base_image-20191013.raw
-rw-r--r-- 1 root root 3670016000 Oct 13 13:30 usbarmory-mark-two-debian_stretch-base_image-20191013.raw

dpavlin@nuc:/mnt/klin/home/dpavlin/usb-armory/usbarmory-debian-base_image$ dd if=usbarmory-mark-two-debian_stretch-base_image-20191013.raw of=/dev/sdb bs=1M

dpavlin@nuc:~$ dmesg
[764607.538898] usb 2-1: new high-speed USB device number 34 using xhci_hcd
[764607.689068] usb 2-1: New USB device found, idVendor=0525, idProduct=a4a2, bcdDevice= 4.19
[764607.689078] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[764607.689082] usb 2-1: Product: RNDIS/Ethernet Gadget
[764607.689100] usb 2-1: Manufacturer: Linux 4.19.78-0 with 2184000.usb
[764607.900916] cdc_subset: probe of 2-1:1.0 failed with error -22
[764607.902622] cdc_subset 2-1:1.1 usb0: register 'cdc_subset' at usb-0000:00:14.0-1, Linux Device, ae:47:47:81:a0:a4
[764607.902666] usbcore: registered new interface driver cdc_subset
[764607.902711] cdc_ether: probe of 2-1:1.0 failed with error -16
[764607.902732] usbcore: registered new interface driver cdc_ether
[764607.914234] cdc_subset 2-1:1.1 enp0s20u1i1: renamed from usb0

dpavlin@nuc:~$ sudo ifconfig enp0s20u1i1 10.0.0.2 netmask 255.255.255.0

dpavlin@nuc:~$ ssh usbarmory@10.0.0.1
# password is usbarmory

usbarmory@usbarmory:~$ uname -a
Linux usbarmory 4.19.78-0 #1 PREEMPT Sun Oct 13 11:05:18 UTC 2019 armv7l GNU/Linux
usbarmory@usbarmory:~$ cat /proc/cpuinfo
processor	: 0
model name	: ARMv7 Processor rev 5 (v7l)
BogoMIPS	: 109.09
Features	: half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae
CPU implementer	: 0x41
CPU architecture: 7
CPU variant	: 0x0
CPU part	: 0xc07
CPU revision	: 5

Hardware	: Freescale i.MX6 Ultralite (Device Tree)
Revision	: 0000
Serial		: 0000000000000000
usbarmory@usbarmory:~$ free
              total        used        free      shared  buff/cache   available
Mem:         512204       25588      436744        7624       49872      467984
Swap:             0           0           0