Semicircular edge, comfortable in hand, optical glass prisms set, 18pcs packed into a luxury leather case $165/set, more than 10sets at $160/set.

18pcs indicidual prisms also available
( available with 1, 2, 3, 4, 5,  6, 7,  8, 9, 10, 15, 20, 25, 30, 40, 50, 60, 80)