The lever handle is prevented from rotating with a new re-designed concave washer, that consist of two parts - a base that hold the lever handle in place so it doesn't rotate, and a concave insert. The concave insert are made from a low fiction and self lubrication material called POM, that make it possible to open and close the quick release with ease. The lever handle are also made longer and the cam bigger, providing plenty of clamping force.
These improvements are all done without sacrificing on the low weight. At only 21 grams, Brompfication's Seat Clamp Quick Release saves 34 grams over the original! The brass version is a bit heavier, but still saves you about 19 grams. All aluminum parts are CNC machined from 7075-T6 aluminium, and axle and barrel nut and made from titanium grade 5.
Aluminium version 21 grams, brass version 38 grams.