I am currently using the Olin. They don’t make one that fits it exactly and I believe I ended up ordering one for the diamondback hd because it had the closest inner diameter. I wrapped the eye piece in athletic tape and it works at it should. Do have to replace the tape every couple months. I will double check the size and get some pictures after work
I basically just wrapped athletic tape on the eyepiece until it was snug then pushed it on. I also made sure to center iPhone camera to the eyepiece as best as I could. It works. And I did double check and the size was for the Diamondback HD. I also include some pictures. The 3 axis bucks were at 390, the billies were at 420, and the small herd of axis deer were at 360 for reference.