PoolTree System -- Bungee Assembly - Bungee Connector, Cord, & Strap with Buckle Replacement part for the PoolTree System: Winter Cover Support System. For use with any PoolTree System - The industry's only self-cleaning winter cover support system for above ground pools. When used with a mesh cover, our PoolTree System eliminates the need to scoop leaves, pump off the cover, or dump dirty water into the otherwise clean pool.