I made my first pair of bones from an old Bois d?arc fence post and taught myself how to play them. They rendered a beautiful, clear, bell-like sound. I made another pair, with minor improvements, so I could play with both hands. A lot of sets later I have made a set that I consider the ultimate bones design. Nothing makes bones like 100 year old Bois d'arc fence post! A pair of bones is 2, for single handed play and it takes 2 pair to make a set, for double handed play. The ones I made for myself are 1 inch wide by 8 and 3/4 inches long. The right pair, top bone is 5/32 thick, the bottom one 6/32 inches thick (base). The left pair, top bone is 4/32 thick, the bottom one 5/32 inches thick (Treble). Traditionally bones are held close to one end, and the opposing ends are clicked together ... one striking point. My bones are designed to be held in the middle with finger grooves to keep them from walking. This gives 2 striking points per pair and 4 per set. My bones are balanced, so that they weigh the same on each end of the groove. When held together the striking surfaces are mated for a perfect strike every time. I mark them so I can hold them the same way every time. The left hand pair (the thin pair) has red finger grooves and one of them has a red end ... it always goes on bottom. The right hand pair has black finger grooves and the one that goes on bottom has a black end.