Hi Everyone .... I came across these eyepieces on the web. These come in 16,20 & 24mm being argon purged waterproof. The reviews I have read are positive. I was just wondering if anyone has tried using these in the 65mm Pentax. I have been looking for a low power (16x) waterproof eyepiece that performed well but would not be too costly. I was curious about the 24mm, would it focus properly ? With this eyepiece it would have about 16x with 18mm of eyerelief, cost on line $119 US. ...gwen