Dongle to connect T1 control to sentry sw:
Have two usb and one serial port version. $49 each
USB direct to T2+ :
One only $49
Both of these allow monitor function.
Extra disconnect cords for multiple vehicles $10 each.
Leave on car; no unplugging 23 pin connector or removing dash each time.
GE LX cables made to order $49 each
Sw may be available to borrow from other members.
Ask here.