We started with the top quality, smooth movement of the Base Lab Tools 200 TPI fine adjustment screws and then we went a step further; we designed in a sapphire sphere for the ball tip. The result is

• Extremely low friction when used against another hard surface (steel), for even smoother, fine adjustments
  
• The exceptional hardness of sapphire makes the tip nearly impervious to scratching and denting.
• Sapphire is chemically inert, and ideal for extreme or harsh environments with exposure to many acids, alkalis, or extreme temperatures.
• Made in the USA

Base Lab Tools' Sapphire Tipped Fine Adjustment are made to order and in most cases can be delivered within 1 week of order.