Modulus Arms

three companies sell this “style” of jig, only the Modulus brand uses 4 retaining screws in a “box” pattern for the left and right side plates, resulting in the most robust jig you can buy, with minimal flexing. one thing that is very important but not mentioned in the instructions, is squaring up the side plates when tightening, don’t rely on just the tapered head screws to line it all up- they may or may not, i used 3/8” and 5/32” brass dowels as i was tightening it up, perfectly square!

I purchased the router jig with 5 billet lowers, router adapter plate for my Skil full size router and extra v4 router bits. I am extremely happy with the products and the service I have received from Modulus. I highly recommend Modulus Arms!

Quality Products. Fast Shipping

Easy website to navigate. Easy to order. Quality product. Fast shipping.

Easy ordering from the site, reliable service with quick delivery, securely packaged (with tracking) and a fantastic product selection of both components, replacement parts, and more. Insofar as the jig itself — amazing quality. Follow the instructions and take your time - don’t rush through multiple milling notches at once, and invest a few bucks in actual cutting oil (available at any hardware store) vs using wd40. First ever lower came out smooth as glass and perfect.