you can get what you need from their application chart..and their charts should be in most suppliers online catalogue etc...any way the options will range from openining size required for fitting on carb..lenght of filter you want...diameter...angle that pod goes..straight/22/45/60 degree etc...just have an idea first what will work on your dads sled...they may or may not have an actual application number but if not its still easy to figure out what to order..they give all the options needed..get the pre-filter socks to go over filter as well..anyway dennis kirk/high performance engineering/motovan/kimpex/parts u.s.a/parts canada/..all good sites that should handle k/n