Amazon has some. Here is a link:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
on this one there is an insertion loss of 4dB.
Another item you want to consider is the Clearstream JUICE. it has done wonders for me. It has LTE filtering and overload protection.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1