Bruno Tilz 213- A 1 1/2 vs Bruno Tilz 213- A 2
The Bruno Tilz 213- A 2 has a wider cup diameter, the Bruno Tilz 213- A 2 has a larger throat opening.
Cup Diameter
The Bruno Tilz 213- A 2 has a cup diameter of 23.00 mm / 0.9055 in compared to 22.50 mm / 0.8858 in on the Bruno Tilz 213- A 1 1/2 — a difference of 0.50 mm / 0.0197 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a very shallow cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Bruno Tilz 213- A 2 has a wider throat (4.60 mm / 0.1811 in vs 4.40 mm / 0.1732 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Which is better?
Both mouthpieces are categorized as "Catalog" — the physical dimensions above will determine which suits your embouchure and playing style better.