Yes, only the horseshoe part collects water. Ours is on a large house roof so that particular butt fills really quickly. The downpipe was too wide for most other kits (4inches ish if I recall) so we went for this type. you just cut a small hole which hasn't caused an issue with the downpipe. The part inside is a flexible material so you can force it through the hole and it opens up. It's been working fine for a year now.
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