For type 1:

• High Quality 6063 T6 Aircraft Grade Aluminum Alloy
• Installation is more convenient and stability is better.
• Bubble level design makes it easier to aim.
• Suitable for 11mm Dovetail Rail.
• Fit for both 30mm and 25.4 mm (1 inch) body tube rifle scopes.

For Type 2:

• Type: Low Profile. Material: High Quality Aluminum. Solid aluminum alloy factory stand with shock and Recoil
• Quick Detachable Design for Fast Installation or Detachment. See Through Style.
• Fits on 20mm Picatinny weaver rail mounts. Inner Ring Diameter: 30mm(with 25.4mm diameter adapter ring)
• Scope rings are for standard scopes 1''25.4mm/30mm scope tube
• Designed to install a Flashlight, Red Dot or Rifle Scope onto the 20mm Picatinny/Weaver Rail.