The cutter is OK (very good for the price!), but it is not the one in the picture (the picture is probably distorted as the punch looks much smaller in it). This one is 110 (L) x 30 (W) x 28-57 (H) mm, 186 g, stapler size but heavier.
My plan was to keep this with me when abroad - to use cheap prepaid connections - but for this weight, I'll punch me a template of an old sim: I can use it to draw size and cut with scissors.
Sim adaptors are pieces of cheap plastic with a simple cut-away hole for the micro-sim. You need to attach accompanying stickers of metallic paper if you want backing for the sim card.
Probably best to use the remaining of the cut sim, as it is more tight fit and material is better. You do need to trim the edges a bit for that, as the punch result is not perfectly clean cut.