Until recently, options for non-incandescent light bulbs were fairly limited. There were the cheap and effective but harshly lit CFL bulbs, the expensive but high-quality LED bulbs, and the cheaper ...
An LED light that runs on rope pulls and gravity has been developed, which could be good news for developing countries without access to stable lighting. GravityLight, a crowdfunding campaign and ...
Some results have been hidden because they may be inaccessible to you
Show inaccessible results
Feedback