The RGD421 is an RGD series guitar introduced in 2012 as the replacement model for the RGD321. The RGD421 removed the tone knob, pickup selector, and check mark inlays, and included a new mid-cut EQ switch and black pearl dot inlays. The RGD421 is the hard-tail version of the RGD420, which featured an Edge Zero II tremolo. A 7-string version was also released that same year, called the RGD7421.
The RGD421 features a 26.5" scale neck and comes a full-step down in factory D-Standard tuning (DGCFAD). Other features include a Wizard III neck, Gibraltar Standard hard-tail bridge, and CAP-VK1 and CAP-VK2 passive pickups.