Cheap And Discounts Aluminum Triangular Scale Ruler Architect Ruler Drafting Ruler for Engineers 1:100 1:200 1:250 1:300 1:400 1 Dropship Wholesale. Buy Directly From Merchant Castleof threeC Store. Enjoy ✓Free Shipping Worldwide! ✓90 Days Buyer Protection. ✓Easy Return. ✓Money Back Guarantee.