NP-277 Polypropylene Cup This is the newer type cup. Certainly very durable and reliable. In the newer sprayers B & G replaced the NP-271 Leather Cup with this hi tech molded cup. Both work well, although the leather is a little easier on the brass. That being said we never have heard of the polypropylene inverting while pumping up a sprayer.
This is # 13 on Page 4 in the 2009 Complete Extended Repair Manual.
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