There was a Primus 210 on our local online auction site with a silent burner. So I brought it. The stove is nothing special. Just your typical Y stamped 210. The burner however is. At least to me. It’s a silent burner with a fixed row of burner holes and a top cap. The inner cap is smaller than usual and the inner cap of a number 5 is nearly the same diameter as the outer ring and a standard No5 outer cap fits over the entire outer of the burner. Have I lucked out and got an early No4 burner. Rrgular later No5 caps on the left