The two piece bug proofing system covers entire crib with easy access to your child. Hoop net bottom easily fits over structure with elastic band at top of rail. Net hangs freely around structure with bottom secured under all four legs. The top net fits easily over the sturcture keeping baby safely away from mosquitos, other insects, and pets. Carriages, bassinets, tandem strollers and strollers require top net only. Use according to instructions - to be used with (not in place of) parental supervision.