Part Number R21-4-5.00A-9191-4-V Circuit Breaker Accessories in stock with ready to ship. Get an instant quote for Sensata Technologies Inc part number R21-4-5.00A-9191-4-V by filling form below with your desired order quantity, targeted price and the expected order-fulfilment date. Get instant quote for R21-4-5.00A-9191-4-V. Our dedicated account manager will get back to you within 15 minutes.