the drainage valve set by GARDENA is used for drainage at the pipeline, sprinkler and original GARDENA system, in the set are a standardized car air valve and the three different attachments original GARDENA system, original GARDENA system nipple as well as Profi system nipple, these can then be used for drainage at the pipeline sprinkler and Profi system, to protect them from frost damage, the operation is easy and first the air valve is screwed onto an attachment appropriate for the system, now compressed air is generated with the help of an ordinary bicycle pump or compressor, the compressed air blows through the system and frees it from possible water residues, besides it is a quality product Engineered in Germany