Over the decades I’ve played every kind of blowpipe valve invented. While those that insert into the blowpipe stock or are built into the plastic stick are excellent, those that plug into the end of the blowstick can be terribly restrictive of air flow into the bagpipe, making the pipes harder to blow. I constantly come back to the original“flapper” valve. Now made out of rubber (rather than leather), these are maintenance-free, last for years and in no way restrict air flow. I find them well worth the effort of hemping on to the blowstick. When you do so, make sure the valve sits perfectly flat on the end of the blowstick before you hemp it.