ASLI (Angle Slope Level Indicator)

Slope and cant Level Together in One Unit
The Horus ASLI™ device gives the long distance shooter a slope indicator and cant indicator in a single, precision engineered, hermetically sealed unit so you don't have to hang multiple gauges off your rifle like ornaments. It's reversible and can sit on either side of the scope, accommodating both right and left-handed shooters. The ASLI eliminates guesswork in uphill and downhill shots. To find the true horizontal distance, simply multiply the range to the target by the cosine value shown on the slope indicator. For long-range shots, the cant indicator is invaluable for keeping your bullet flight true to your sighted aim. It attaches directly to your scope, can be painted to match your scope's camo finish, and doesn't need batteries.

The ASLI comes with a hard rubber cap, tin storage box, and your choice of one mounting option (30mm mounting ring, 34mm mounting ring, Picatinny side rail).

For extreme-range mission-critical hits, enter ASLI values into our ATrag ballistics software. You can also use the ASLI with our CATS Targets to achieve perfect alignment between your scope and rifle. Pinpoint accuracy at extreme range requires pinpoint alignment.

$70   ASLI with 30mm ring
$70   ASLI with 34mm ring
$70   ASLI with rail mount

Related Accessories

30mm mounting ring

Extra mounting ring

Learn more  >

34mm mounting ring

Extra mounting ring

Learn more  >

Picatinny rail mount

Extra side mount

Learn more  >

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Features Specs Brochures Manuals Demos


  • Magnetically dampened to quickly halt oscillation for fast readings
  • Clear, large numbers for better visibility in low light
  • Readings in both vertical angle degrees and corresponding cosine value
  • Versatile mounting for left, right, bubble up or upside down
  • Easy-to-paint plastic housing, to blend ASLI into your scope and gun
  • Tested to withstand the repeated G-shock pounding of a 50cal BMG
  • Excellent for high- and low-angle shooting
  • One mounting ring included, choose from the following: 30mm ring, 34mm ring, Picatinny side mount. You may purchase extra rings at additional cost.
  • Storage case and hard-rubber cap included



  • Height: 1.8 inch (4.6 cm)
  • Width: 1.5 inch (3.8 cm)
  • Depth: 0.8 inch (2.1 cm)
  • Weight: 1.5 oz (42.5 gr), 2.0 oz with cover



Accessories Brochure
Aiming Accessories brochure in PDF format,765 kb download. Click here to view now.

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ASLI Manual
How ASLI works. User's manual in PDF format, 807 kb. Click here to view now.

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ASLI Product Demo
Measure cant and slope while looking through your scope. Click here to view now.

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