Amazon offers Prime members the Kohler Touchless Toilet Flush Kit, model no. K-1954-0, for $33.33 with free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $7.17.) That's $17 under our mention from two weeks ago and tied as the lowest total price we've seen. (It's also the best deal now by $7.) It's compatible with most canister and flapper toilets, but not with dual-flush, top-mount flush, pressure-assist, or ballcock valve toilets.