My wife and I decided to take an impromptu trip to Belize this month, and we wanted to do a bit of snorkeling. Since I'm highly myopic in one eye, and nearly that in the other, I needed a mask with corrective lenses—quickly. GetWetStore offered corrective lenses in half-diopter steps and quick turnaround. I ordered -7.5 diopters for my left eye and -5.0 for my right. I placed my order on Sunday afternoon, with Priority Mail shipping, and the mask arrived on Wednesday. After testing it out in a pool, I'm very pleased. It fits perfectly and the correction is exactly what I requested. (It seems that my right eye has gotten a bit worse since the prescription I used, but for snorkeling, the correction is good enough.) The purge valve works like it should. I'll be using the mask on a dive in two days, and I'm looking forward to being able to see what's around me.