2/ We have lots of "gecko cajon" sound testing videos in Youtube which you can check the sound online.The link is : https://www.youtube.com/results?search_query=GECKO+CAJON or u can open youku link http://www.soku.com/search_video/q_gecko%20cajon?spm=a2hww.20023042.#qheader_search~10&_rp=1489561388760HUb1BR to check more my cajons playing and teaching videos.