good material...but yet to fully test it!
I chose this adapter because the eyepiece of my spotting scope is 50mm in diameter. all other available adapters are up to 48mm. The adapter is suitable to up to 53mm. However it is hard to setup and once it is ajusted to the scope and attached to the phone it has to stay attached otherwise it has to be realigned all over again. If the phones camera isn't in the middle of the phone light may leak and reflect into the picture. took 14 days to arrive, communication with the seller was not necessary.