Router Jig Extreme™ Tool Kit w/SpeedMill™


The Router Jig Extreme™ tool kit contains our custom designed SpeedMill™ and all drill bits you need to complete your 80% lower receiver build.

Kit Includes:

  • 3/8 Drill Bit.
  • 21/64 drill Bit - custom designed for deep hole drilling and chip clearance.
  • 5/32 drill bit.
  • Custom SpeedMill™ - You must select proper SpeedMill™ to correspond with associated router. (see table below)
  • Made in USA.

Confirm SpeedMill Type

We strongly recommend all customers to only use our proprietary end mill, the Modulus Arms SpeedMill™ with our 80 lower jig. 

Please see the chart below for which routers we recommend to use with our corresponding SpeedMill™ versions (there are 4). You can also pick up a Tool Kit if you want spare tools.

If your router is not on any of the lists, then it is not compatible with our products and we do not recommend using it to complete an 80 lower with Router Jig Extreme™. Please note that all routers that use V4 will need the Large Router Platema-routerchart-website-01.jpg

*Satisfaction Guarantee

Our products are protected by multiple issued and pending US Patents.

It’s possible that some, very rare and oddly shaped non-milspec AR designs will not fit this jig. In the unlikely event that your 80 lower doesn’t fit you may return the jig for a full refund or consider buying one of our 80% lower receivers instead!

DISCLAIMER: Under California Law, it is illegal to manufacture, complete, or assemble a firearm using any unserialized Firearm Precursor Part or unserialized Parts Kit. By ordering this product, you are confirming that your conduct complies with California Law.

Router Jig Extreme™ Satisfaction Guarantee Policy: Satisfaction is guaranteed. We are completely confident that you will love the Router Jig Extreme™. If for any reason you are not satisfied with it, you may return the Router Jig Extreme™ for a full refund minus shipping costs within 30 days. Just contact our customer service team for a return authorization and be sure to save the original packaging. All pieces must be returned in good condition with original packaging. Lifetime Replacement Warranty: Modulus Arms 80% lowers are nearly indestructible and are covered by our unconditional lifetime replacement warranty. If you somehow manage to destroy a Modulus Arms 80% lower in a way that stops it from working properly, we will replace your lower with a new one free of charge. Damage caused by milling your 80% lower out incorrectly and intentionally inflicted damage is not covered. Return policy: Modulus Arms products may be returned within 30 days for a refund as long as they are in unused condition. Products which are not made by Modulus Arms such as magazines, lower parts kits, etc. are all returnable within 7 days as long as the original packaging is unopened.