The length of the 5mm and 4mm Adjustable Punch Needle is 123mm. The internal diameter of the 5mm needle is 4.5mm, the exterior diameter is 5.5mm so it is possible to punch with wool up to 3.5mm aka chunky and super chunky yarns. The interior diameter of the 4mm is approx 3.5mm and it is suitable for light weight yarns such as light double knit.
The adjustable punch needle comes with a wire threader. To change heights of your loops you simply twist the needle, slide to the punch desired slot / height and twist to click back into place.
The mini has 3 needles (Large, Medium and Small) which are interchangeable. The small and medium are for lighter weight yarns (3) and the large is for medium size yarns (4) aran weight wool.