This is now the K & M sheet brackets past fortunately. The 15 mm wide contact surface presses a nothing. The brackets are 5 cm long and to press very well through the round printing surface. Being tight, but not too tight, fix the sheet.
The white prints (notes and the K & M - Logo) make them appear dibasic. Inasmuch as the brackets are provided differently than depicted. What I find very good.
There is nothing to complain about.
The price is 100% okay. Buy recommendation.