MLCS Router Bit Bearing Guides have totally enclosed ball bearings.

Features:

• Calculating Bearing Size for Desired Depth of Cut:
  Bearing Outer Diameter = Large Diameter of Bit - (2 x Desired Cut Depth)
• Please measure your bearings accurately before ordering.
• Note: By replacing your router bit's bearing with a bearing that has a smaller or larger Outer Diameter, you can achieve a different depth or profile.

Specifications:

• (B) Inside Diameter: 5mm (approx 3/16")
• Outside Diameter: 19mm (approx 3/4")
• Bearing Height: 6mm