In one embodiment, a closure system comprises a guide assembly having a channel defined by a first guide wall and a second guide wall. The closure system may include a retention bar extending into the channel from the first guide wall and a plurality of slats. Each slat of the plurality of slats may be configured to interlock with another of the plurality of slats. Each slat may have a retention groove with at least one sidewall configured and dimensioned to engage the retention bar to retain the slat within the channel.