Dual Tetrahedron 28

This is a four piece coordinated motion puzzle. I called this kind of my puzzles NEW RANGE. When I started to sand my puzzles, I discovered new possibilities in oval and rounded shapes. These shapes and using different contrasting woods created this kategory. Some of them I called as Ocvalhedron, Flowers, Bicones ... and they have specification as number so I can orientate in these various puzzles.