Peace, mercy, and blessings of God be upon you. Good evening. Deflation and fast inflation needles, a set of (4) pieces. Honestly, the difference is about double, both in deflation and inflation. They have been tested for filling with a tire shop air compressor and a regular compressor. Regardless of the speed, it will be a reason, by God's will, to extend the life of your compressor. The small needles make the compressor muffled, and the compressed air returns to the compressor itself, which may cause the compressor to overheat and burn out, God forbid. The price for the (4) pieces is 12 riyals. For bulk purchases, we will not fall short, God willing, and the quantity is good, God willing. Shipping is on the buyer if applicable. They replace the regular needles directly on the tire valves of the vehicle. Regards.