Product review (5 stars): worked perfectly but....
I originally purchased this knob set at Home Depot for $18. and found they worked perfectly.  I have an apartment building and the original gas range knobs are usually destroyed by the tenants and these knobs turn an old gas range into looking new again. There are two sets of stem adaptors included in the package and I found that in some cases I need to install both sets on each regulator stem for the knob to work properly.  I have ordered about 8 sets from Amazon and usually replace the knobs with each tenant move-in.  It dresses up the stove and I never had a problem with the operation of the gas range.