From the notice

NSN 6X-5330-LWM044207, TDP VER 005, QTY 20 EA, DELIVERY FOB ORIGIN. NAVSUP Weapon Systems Support intends to solicit, on a sole source basis, spare replenishment from Cometto SPA (A5383) for the procurement of 20 EAGasketKit, P/N# C087.0103.00. AMC 3. ACQUIRE, FOR THE SECOND OR SUBSEQUENT TIME, DIRECTLY FROM THE ACTUAL MANUFACTURER. AMSC C. This part requires engineering source approval by the design control activity in order to maintain the quality of the part. Existing unique design capability, engineering skills, and manufacturing knowledge by the qualified source(s) require acquisition of the part from the approved source(s). The approved source(s) retain data rights, manufacturing knowledge, or technical data that are not economically available to the Government, and the data or knowledge is essential to maintaining the quality of the part. An alternate source must qualify in accordance with the design control activity's procedures, as approved by the cognizant Government engineering activity. The qualification procedures must be approved by the Government engineering activity having jurisdiction over the part in the intended application. If one source is approved, AMCs 3, 4, or 5 are valid. If at least two sources are approved or if the data is adequate for an alternate source to qualify in accordance with the design control activity's procedures, AMCs 1 or 2 are valid.