---BR-147 Small Plug Ear Gauge, graduated cavities measure:
3x12, 4x12, 5x12, 6x12, 7x12, 8x12, 9x12, 10x12, 11x12, 12x12, 13x12
---BR-148 Medium Plug Ear Gauge, graduated cavities measure:
14x12, 15x12, 16x12, 17x12, 18x12, 19x12, 20x12
---BR-171 Large Plug Ear Gauge, graduated cavities measure:
21x12, 24x12, 27x12, 29x12
---BR-172 X-Large Plug Ear Gauge, graduated cavities measure:
31x12, 33x12, 36x12