These outhaul blocks are for round booms like Sunfish type rigs, Although class legality for any class is not known. These fit 35mm ID round booms.
On May-11-08 at 15:43:00 PDT, seller added the following information:WE COMBINE SHIPPING WHENEVER WE CAN, SO MULTIPLE ITEM PURCHASERS PLEASE WAIT FOR US TO SEND AN INVOICE AND WE WILL SAVE YOU SOME$$