Chef, Westinghouse 4 Position Rotary Oven Select Switch - Part # 55869, 3070521WS.Chef, Simpson, Westinghouse Oven Selector Switch. Genuine Part No. 55869, 0534001695. Other Part Nos. 3070521WS, 9980A, Oven function select switch used in many late model underbench ovens. Suits some Chef Select models. 6mm D Shaped shaft. Switch has two diagonal locating lugs either side of the shaft. Contacts rated 10Amp. Fits many late model stoves. Note there are other switches that look identical. There is also at least one other switch with the