Belton Micalex New Eight Pin Octal Chassis Mount Tube Socket For 6L6GC, 5U4GB, KT88, EL34, 6V6GT, 5Y3GT, 6SN7GTB And Similar Tubes. Micalex body, molded in tinned saddle, fine contact integrity. Mounts above or below the chassis. On a sample socket I measured 1.175" diameter above the metal saddle, 1.75" diameter below the metal saddle. Metal saddle itself measures 1.973" X 1.355". Mounts to chassis with two machine screws. Mounting centers approx. 1.625"; mounting holes are slotted allowing good latitude of adjustment. Slot openings measure .231" long overall.