There are other Brands out there and they work much the same.

For most Residential Boilers the following 4 tanks are mostly used.

The # 30, the # 110, the # 15, and the #109.

Some larger homes need the #60

Note: The #110 and the #30 are the exact same size tank, but they are not interchangeable.

The #110 is part of a Fill-Trol System and only screws into a Fill-Trol fill valve.

There are 2 types of Fill-Trol fill valves,

one has a valve handle to turn the water off the other does not.

In the pictures below you will see both of them.

Fill-Trol With Handle and Fill-Trol With Out Handle.

The #110 and the # 109 will only screw into one of these valves.

The #15 and the # 30 will screw in to any 1/2" iron pipe size fitting.

The #109 and the #15 are also the same size as each other.

but about 1/2 the size of the #30 and The #110.