Aspects and techniques of the present disclosure relate to an internal cover/vent handle arrangement, in association with a container, such as a 5 gallon bucket with a slanted sidewall for evacuating air volume above stored material. The disclosure relates to a squeeze-actuated vent valve arrangement arranged and configured to be easily operated even while deeply recessed in the bucket. The disclosure also relates to a deflectable outer seal arrangement configured to seal against a slanted sidewall of a bucket.