Sunoptics is a company that offers scope mounts in fixed or adjustable configuration. They are especially known for their adjustable mounts which are very useful in combating barrel droop in many air gun models. Most  firearms and air guns tend to shoot a bit low when a scope has been mounted and sometimes the scope doesn't have enough clicks of adjustment to compensate for that reality. So using an adjustable mount allows the shooter to use the mount to compensate for most of the barrel droop and the scope is then needed only to fine tune the last little bit of needed compensation. In the air gun world that is a huge help because the closer distances airgunners shoot often results in a lack of enough clicks of adjustment for barrel droop compensation.