Extar’s take: Due to the EP platforms raised top rail, we normally recommend low-profile sights to reduce height-over-bore. Unfortunately, most picatinny iron sights on the market are designed for the AR platform and not many low-profile iron sights are on the market. We recommend these Strike Industries Polymer Backup Sights because of their high-quality construction, easy adjustment, and the backup sights when flipped down. We have confirmed fit with these optics on our firearms and Strike Industries is a trusted accessory partner of Extar.

The Strike Polymer Backup Sights is a low-profile affordable sighting system that is designed for the AR platform and has bonus built-in sights when flipped down. No time to flip up the sights, you have backup sights on your backup sights. The SPBUS sights are made with lightweight and durable SI Polymer Extreme material with steel mounting tab and insert that can handle any wear and tear you throw at it without any major issues.

As long as you’ve got a Picatinny rail, you will have these SPBUS mounted in minutes. Both sights are capable of flipping down nice and low so you don’t have to worry about them being in your way when they’re not in use or snag on any gear. The SPBUS does not have an internal spring so you don’t accidently deploy the sights when you don’t need them.

Since the SPBUS sights are slightly taller than standard A2 sights (2.3mm/0.09" taller), the SPBUS is designed and optimized to have both sights paired together and not with other sights. To zero the sights or make any adjustments, the rear sight has an easy-to-use knob for adjusting windage while the front sight elevation is easily and quickly adjusted without tools.

The rear SPBUS has dual apertures at 4.70mm(0.19") for longer eye relief, low light and faster target acquisition; and 1.75mm(0.07") for shorter eye relief and greater accuracy. Quickly slide the rear sight up and down to change to the aperture you need. If you need these as a primary or want them as a backup sight, the Strike Polymer Backup Sights (SPBUS) is a low-profile durable multi-function option that has tool-less adjustments paired at an affordable price.

PACKAGE CONTENTS:

• x1 SPBUS front sight (fully assembled)
• x1 SPBUS rear sight (fully assembled)
• x1 Hex tool [2.0mm]
• x1 Loctite® Threadlocker Blue 243®

PRODUCT FEATURES:

• Built-in backup sights when flipped down for quick target acquisition
• Low-profile and low snag design
• Tool-less adjustments of windage and elevation
• Quick sliding dual aperture rear sight
• Steel mounting tab and insert for added strength
• Manual deployment so you don’t accidentally deploy when you don’t need
• Front sight can be painted to user's color preference
• Budget-friendly cost-effective option
• Lightweight and durable custom blended SI Polymer Extreme material

PRODUCT SPECIFICATIONS:

• REAR SIGHT APERTURE SIZES:
• SMALL: 1.75mm(0.07")
• LARGE: 4.70mm(0.19")

(When Stowed)

• HEIGHT ABOVE RAIL:
• FRONT: 0.54"(13.82mm)
• REAR: 0.56"(14.20mm)

• LENGTH:
• FRONT: 0.81"(20.57mm)
• REAR: 0.82"(20.93mm)

(When Deployed)

• HEIGHT ABOVE RAIL:
• FRONT: 1.77"(44.91mm)
• REAR: 1.76"(45.34mm)

• LENGTH:
• FRONT: 1.90"(48.26mm)
• REAR: 1.90"(48.21mm)

• Height above standard A2 sights: 2.3mm(0.09") taller
• Rear sight center of aperture to top of rail: 1.51" (38.30mm)

Front sight elevation adjustment:

• At 14.5" sight radius = 1.71"/100 m MOA per click
• At 20" sight radius = 1.24"/100 m MOA per click

Rear sight windage adjustment:

• At 14.5" sight radius = 0.49"/100 m MOA per click
• At 20" sight radius = 0.35"/100 m MOA per click
• FRONT SIGHT:
• LENGTH: 26.00mm(1.02")
• WIDTH: 20.50mm(0.81")
• HEIGHT: 50.02mm(1.97")
• WEIGHT: 0.60 oz

• REAR SIGHT:
• LENGTH: 26.00mm(1.02")
• WIDTH: 20.50mm(0.81")
• HEIGHT: 50.14mm(1.97")
• WEIGHT: 0.70 oz