Arca-Swiss compendium...How do I use with filters?

I am the happy owner of an Arca-Swiss F-line 4X5 view camera, and purchased the A/S compendium lens hood recently. The compendium has 6" slots on both front an d rear for insertion of filters. I got a couple of A/S filter holders which fit into these slots, but the circular cutout in the middle of the holder is greate r the 4"...the packaging indicates these holders are for 125mm (square) filters. Does anybody know if filter holders for 4" filters are availble for use with t he compendium? Are 125mm filters readily available in the US (or even made any where)? I would like to be able to mount filters in the compendium itself since there is clearly the provision for doing so, and avoid having to use a separate, lens-mounted holder, which could possibly be a source of vibration as well as a bit of a hassle to use. Thank you for your help.

Sicerely, Ken

Sinar made (makes?) high quality 125mm width resin filters.

I just found out from Mr. Martin Vogt of Arca-Swiss that they manufacture a meta l 4" filter holder for the Arca-Swiss compendium. It accepts up to 4" X 6" filt ers, and allows rotation of the filter if desired. I have been pleased on more than one occasion to speak with Arca-Swiss in Switzerland, finding them to be mo st eager to help answer any questions. I have read elsewhere in this site about concerns regarding customer support from Arca-Swiss, and can only make postive comments regarding my dealings with them. The F-line camera is beautifully buil t and designed. It is MUCH more rigid that the Sinar F-2, which I was able to c ompare side-by-side with the Arca-Swiss at my favorite giant photo store in NYC. Thanks for the great web site, and for the response.

Sincerely, Ken