3BTB 45-50alternative is EM-4-50/6DS Plastic Fan wheel for 3BTM-CO 25-20-0/22/ Not availablealternative is DA146x240CW EM-4-50/6DS SSR20-524D-1 NU 16-30-4 / 1285alternative is NET5T16PVN001 NET5T16PVN001 3FGM 90-40-7V/1 40101728/1 obsolete/replaced with 48-4-100/6DSL Brand Remco RET4T18PNN001 R18-25/009 DA146x240CW 3- 042-100 22321101 3FGB-CO 85-38-6V/2 Obsolete Replaced from brand Remco 48-4-100/6DSL 1893000474 SSR20-524D-1 impellers for 3BTM-CO 15-20-0/12alternative 3BTM25.20-A-0/122+ 22321095