The military packaging authorities modified long-standing military specification MIL-B to MIL-PRF on April 30, 2001. The materials used and the specified method of manufacture remained the same, but the specification numbers changed. For example, MIL-B-131 became MIL-PRF-131. Below is a chart reflecting the change.

MIL-PRF-121 Type I Formerly MIL-B-121 Type I, Grade A, Class I
MIL-PRF-121 Type II Formerly MIL-B-121 Type II, Grade A, Class 1
MIL-PRF-131 Type I Formerly MIL-B-131, Class I
MIL-PRF-131 Type I, Class II Formerly MIL-B-131 Class II
MIL-PRF-131 Type I, Class III Formerly MIL-B-131 Class III
MIL-PRF-22191 Type I Formerly MIL-B-22191 Type I
MIL-PRF-22191 Type II Formerly MIL-B-22191 Type II
MIL-PRF-81705 Type I Formerly MIL-B-81705 Type I
MIL-PRF-81705 Type II Formerly MIL-B-81705 Type II
MIL-PRF-17667 Type I Flat Formerly MIL-P-17667 Ty. I , Cl. I Neutral wrap
MIL-PRF-17667 Type II Creped Formerly MIL-P-17667 Ty. II Cl. I Neutral Wrap
MIL-P-130 Type I crate liner medium duty
MIL-P-130 Type II Crate liner Heavy duty
MIL-DTL-117 Formerly MIL-B-117

We offer a range of mil spec materials that are certified to the specifications listed above.  To see all the barrier materials we carry click here. Please note, specifications for materials are not the same as specifications for bags and tubing.  All bags and tubing adhere to MIL-DTL specifications.