Pourers are the alternative to spirit measures. They come in the usual 25ml, 35ml and 50ml sizes, plus the unmeasured 'freeflow' models.
Freeflow pourers are often coupled with thimble measures to allow easy variance on the measure size desired, which is not possible when using spirit measures.
Please note: Measured pourers are not government stamped. If used to retail controlled spirits, thimble measures should also be used to verify fluid volumes.