link to buy:
http://www.aliexpress.com/store/product/R250-Leroy-Somer-AVR-Automatic-Voltage-Regulator-for-Generator-Alternator/435962_32316611085.html
Other Models AVR
Stamford AVR:MX341,MX321,SX440,SX460,AS440,AS480,EA440-T,MX450 Leroy Somer AVR:R230,R438,R448,R449,R250,R450 Marathon AVR:SE350,EA350 Siemens/Basler AVR:AVC63-7/7F,AVC63-7-1A,AVC63-7FS,AVC63-4,AVC63-4A Marelli AVR:M40FA640A,M16FA655A Universal AVR:GAVR-8A,GAVR-12A,GAVR-15A/B,GB-15A Others:EA05A,EA05AF,EA15A-2,EA04C,EA63-7D,EA06/UVR6,SR7 Caterpiller:VR6 Engga:WT-2 WT-3