View stup06i stup5g4 series datasheet:

STUP06I - STUP5G4 SURFACE MOUNT TRANSIENT VOLTAGE SUPPRESSOR VBR : 6.8 - 440 Volts SMA (DO-214AC) PPK : 400 Watts 1.1 ± 0.3 FEATURES : * 400W surge capability at 1ms * Excellent clamping capability 0.2 ± 0.07 * Low zener impedance 1.2 ± 0.2 * Fast response time : typically less 2.1 ± 0.2 2.6 ± 0.15 then 1.0 ps from 0 volt to VBR(min.) * Typical IR less then 1µA above 10V * Pb / RoHS Free 2.0 ± 0.2 MECHANICAL DATA Dimensions in millimeter * Case : SMA Molded plastic * Epoxy : UL94V-O rate flame retardant * Lead : Lead Formed for Surface Mount * Polarity : Color band denotes cathode end except Bipolar. * Mounting position : Any * Weight : 0.064 grams DEVICES FOR BIPOLAR APPLICATIONS For bi-directional altered the third letter of type from "U" to be "B