1. 5-7mm
2. 7-10mm
3. 10-14mm
4. 16-20mm
5. 20-30mm
6. 30-40mm.
2 - River Black polished pebbles
1 - 10mm to 20mm
2 - 20mm to 30mm
3 - River Black Fine polished pebbles
1 - 10mm to 20mm
2 - 20mm to 30mm