Axiom 11x7" DD Searchcoil with Focused Core (FC) Dimensions: 11" (27.94 cm) x 7" (17.78 cm) Can Be Used With: Axiom™ Garrett Exclusive! Axiom Focused Core (FC) DD Coils Engineered with a centralized focused core, each Axiom DD searchcoil exceeds mono coil performance on small gold nuggets. DD coil is preferred where the most severe mineral conditions exist. Front half of solid coil’s top surface provides a large, flat surface to spread a handful of dirt to sift for a tiny nugget. Ideal coil for prospectors and relic hunters for improved gliding/scrubbing over brush, rocks, etc. The Axiom's Iron Check function only works with DD coils.