Or you can custom make one for odd sized intake tubes/strainers. I make mine out of a sponge for an Aquaclear 70. This way you know the sponge is aquarium safe and it has large pores so doesn't inhibit flow too much. Bigals also makes their own version of the sponge for $1.50 I think.
Another option, a little more expensive, is the stainless steel mesh intake cover. H4N, a member here on planted tank, makes them for many sizes of filters. They work well and look good too.
I prefer the sponge option, as they add more space for beneficial bacteria to colonize. But some don't like having to clean the sponge occasionally. No point in replacing your entire filter if you can use one of these options to update it. Hope this helps, good luck.
If you want to get creative, you can fit something like a double sponge filter over the intake. That way you can rinse the sponges one at a time and not risk losing your beneficial bacteria.
All it took was a couple pieces of vinyl tubing to turn this:
I have one of the steel intake covers. I don't really like it. It looks nice and works fine, but I find that when I use the sponges a lot less debris get into the filter, and so I don't have to take it apart to clean it as often.
I got a stainless filter guard from h4n and am very pleased. I went from a pantyhose strainer to the stainless. The pantyhose was terrible because it would clog within a day and the filters productivity was greatly reduced. Now my tank is enjoying the max flow from the new guard and have lost zero babies.
How did you connect the sponge filter to the Hob? I have both and would like to rig this up, looks great!
It's just some vinyl tubing. I forget what sizes I used off the top of my head, but I think I found that a 3/4 inch tube fit snugly around the HOB filter intake and 5/8 inch on the sponge filter. The smaller vinyl tube fits snugly in the larger one, so it all holds together very tightly.
Also, that the little 'spout' visible on the back of the sponge filter in that picture is where an air hose is supposed to connect, so when attached to the HOB water was being sucked in there. I plugged it with a drop of gorilla glue.