Medgyn Laminaria Dilator 4mm Medium, 60mm Long (021004). Laminaria is a 100% natural cervical dilator made from a sea-grown plant containing no synthetic materials thus the gradual and uniform swelling of this natural substance is far less traumatic than rapid dilation, making Laminaria the preferred method of gentle dilation or softening of the cervix. 1/EA. Priced per each. FREE Shipping!