The Brother P-Touch 7100 handheld label printer was the cheapest P-Touch specifically targeted at electricians. It will print on TZ tape sizes between 3.5 and 12mm. It has an ABC keyboard, large 1-line display, 9 font styles. It was supplied with a hard carry case and mains adaptor but can run from 6 AAA batteries. This printer has since been replaced by the PT-E100. The E100 prints faster, has specific patch panel and cable marking functions, and can even do serialisation.
The Brother P-Touch 7500 handheld label printer was much larger and heavy duty. It will print up to 7 lines on TZ tapes between 6 and 24mm. It has a large 2-line backlit LCD. It too comes supplied with a hard carry case and mains adaptor but can run from 6 AA batteries. The Replacement PT-E300 is pretty much the same but only takes up to 18mm tape, but with a larger screen and faster print speed, a small maximum tape width shouldn't be too much of a down side. Plus it comes with a rechargeable battery and a QWERTY keyboard. The Brother 7600 handheld label printer has all the same features as the 7500 but also has USB to connect to a computer to design labels templates and upload company logos to the printer's memory.