The caves measure approximately 1.75" wide by 1.5" tall by 5.5" deep, with a backing to create a dark spawning cave. Most bristlenose plecos prefer a cave that is slightly wider than the males pectoral fins, so please make sure these caves are an appropriate size for your fish before purchase. For L-series (hypancistrus) plecos, I also have spawning caves  and condos for them available on my store!

Please let me know if you have any questions!