Product review (1 stars): Poor replacement for Whirlpool dryer - and failed within 2 weeks
My 10 year-old Whirlpool dryer (model LER7648PQ1) stopped heating during the dry cycle. After testing the heating element, cycling thermostat, thermal fuse, and high temperature thermostat, it was evident that the cycling thermostat was bad. The Whirlpool part number for the cycling thermostat was 3387134, so I purchased this cycling thermostat and thermal fuse as a replacement. After the replacement, I tried drying clothes on the "automatic dry" cycle, only to find that clothes never dried completely - the load would end up as either damp or wet. Clearly, the cycles ended prematurely and I had to dry the load a second time. After 10 days, the dryer stopped heating in its entirety. I pulled the "new" cycling thermostat to find the casing had cracked and part of the bimetalic strip within was rattling loose. So I replaced the thermostat with a genuine Whirlpool 3387134 factory part. Loads have dried perfectly ever since; clearly indicating that at least for my dryer, this replacement part is substandard and a poor choice.  I have an Efergy energy monitor, and have attached pictures showing electricity consumption against time comparing the aftermarket thermostat and the genuine Whirlpool thermostat. They are dramatically different.

The aftermarket thermostat (the item being reviewed here - upper graph) holds temperature for a short time (~17:50-17:59), cools down to much lower than 130F before closing again, and then goes through several short heating cycles (18:00-18:25). After which, the dryer has a low energy demand for about 20 minutes (18:28-18:40). Total run time of about 45 minutes, with a load that remained damp and I had to dry them a second time - another 45 minutes.

The genuine Whirlpool thermostat (lower graph) looks very different. The initial cycles are longer, and the thermostat doesn't cool completely before closing (18:30-18:50). After this, it goes through several cycles of decreasing time - as one would anticipate if the load is actually drying, before finishing up just before 19:30. Total drying time was just under one hour, and the load was dried perfectly.

Drying clothes twice due to inappropriate thermostat function wastes time and energy. So, at least for Whirlpool dryers, I do not recommend this aftermarket cycling thermostat.