that PMC now has available
a valve for bags as similar, but not the same, as the SKC (a
2N1 valve which is made of polypropylene. Pricing is the same
for the metal 30-AL type valve, which adds $1 to above prices as of
June, 2015. The metal valve is generally the Dai metal valve with
evacuation cross in the bottom. Other metal valves may be used,
if available and desired by the customer.