Now available, Winch Conversion Kit to convert a Nature House, Trio, ERVA purple martin house system from a rope-and-pulley (with or without a lanyard lock) operation to a winch-and-cable operation. Kit includes instruction sheet and everything needed to convert the following systems: TG-8 Trio Grandma, MSS-8 Martin Safety System, TG-12 Trio Grandpa, MSS-12 Martin Safety System or TM-12 Trio Mini Castle.