I think I bought one from Hayneedle. They had a 10% coupon and free shipping. It was worth the investment for peace of mind.I'm thinking on getting one of those next year before I start with a spring hatch. My DH thinks its too expensive so I'll probably use my birthday money to get one - our agreement is that our birthday money from my mother can be spent however we want. No discussions necessary. I'm thinking its much better all the way around - less energy, less fire danger, less heat in the house and the birds will sleep!