The LTM Portable is a "luggable" BBC Master (it weighs 17.5kg). It has a standard Master Issue 2 motherboard with an internal 6502 Co-processor . It is packaged with a green screen monitor and 2 x 5.25" floppy disc drives in a large, heavy case. It does not include batteries and runs on mains power. From the paper label on the back it appear that the computer was used by the Radio Investigation Service HQ.