The metallic spiral outer catheter is autoclavable and finds it`s way to inner os of cervical canal due to it`s unique flexibility, which no outer catheter out of plastic can achieve. NOTE: due to remarkable price reduction ETFLEX®-Steiner may also be used as disposable product. I invented ETFLEX®-Steiner spiral metallic outer catheter in order to simplify ET procedure in particular in cases of difficult transfers. The metallic, spiral outer catheter finds it`s way to inner os of cervical canal with optimal visualisation at ultrasound. Due to the fact, that in Western Reproductive Medicine disposable products are recommended only, many colleagues use this catheter in extreme difficult ET situations only, which is a contradictio in se.