Hamster zona-free ovum test
The hamster zona-free ovum test (HZFO test), or hamster egg-penetration test, or sometimes just hamster test, is an in-vitro test used to study physiological profile of spermatozoa. The primary application of the test is to diagnose male infertility caused by sperm unable to penetrate the ova.
Source: Wikipedia — Hamster zona-free ovum test (CC BY-SA 4.0)