I don't know how Aventon does it, but it sells this bell--made by Spurcycle--for LESS than Spurcycle sells it. SAME EXACT BELL. I've bought six (the latest two from Aventon) and put them on all my bikes. CLASSY, with a spring-actuated striker that hits the bell with a ringing, LOUD ping. The bell is a bit tricky to install, as you have to hook some metal straps into the body of the bell, making sure the rubber feet that isolate the bell body from the handlebar are properly aligned. The bell sits fine on my 31.8mm handlebars and comes with two metal "straps" that go around the bar: one for 31.8mm bars and a smaller strap for narrower bars.
If you want the best bell out there, GET THIS ONE. People NOTICE it. Looks great, too--small but classy. The bell itself is round and about 1 inch tall and 1 inch wide. Built well, it should be around for decades, I'm guessing.