MOV 15V RMS Dia=8.5mm 1.0 Joules Itm=250A Clamping Voltage=52V
 
The NTE Metal Oxide Varistors feature a barrier layer that gives the user fast response time. These devices have a high transient current handling capability when high voltage is applied. Static resistance is, however, very high under low voltage conditions, permitting low standby drain currents.
 
Full spec sheet:
https://www.nteinc.com/specs/10to99/pdf/movs.pdf