PT maintains inventories at its 16 branch warehouse locations.HBS cam arms are made of 300 series Stainless Steel.HB cam arms are made of Brass.All Stainless Steel castings are 316 and all components are 300 series Stainless Steel.Please call for special quote on complete cam arm assembly and components in 316 Stainless Steel.8, 10 and 12 inch couplers are 4-cam designs with the STA-LOK positive locking feature.Couplings not interchangeable in the industry are sizes 8" through 12".Made in the U.S.A.