-What is the weight difference between LMB-5 and MMB-1 (both in their lightest modes with the MMB-1 having the LWS removed)

-Can the MMB-1 Take 138mm Round Filters?
-If so, does that require the 143mm Back?
-Does the stock back support a 138mm Bellows?

-Are the 4.5" Bellows compatible between the MB20 and MMB-1?

-Does this Adapter Ring allow R4/5 reduction rings?
http://www.cameraaccess.com/camera/m...lter-ring.html

-Is this for clamp rings?
http://www.abelcine.com/store/produc...cat=847&page=1

-What size ring or bellows is required for Zacuto Universal Donut?