I supply Professional photography filters from Formatt Hitech on my workshops, they are free to use along with a 100mm Firecrest filter holder for the duration of the workshop.
As the filters are made of glass there is a "you break it, you bought it" policy sadly.
I can also provide solid tripods for the workshop but on a first come first served basis with large groups.
Alternative if you're interested in purchasing Filters you can go to my