If you have one that won’t wind down, don’t chuck it in the trash. You can shut the breaker off and pull the Spring Wound part out without unwiring the switch. Pull it using a small Torx bit, clean with Isopropyl, give the parts a very light spray with Silicone lube, reassemble. You’ll have a working timer again. You may want to pull the first switch, to get a better idea on the reassembly. BTW If you want to buy them, ZORO Tools has pretty much every model, including ones with the Hold feature.