inputs.text: great sound difficult read display - purchased unit use bicycle 36 hour rides 50100 miles sounds great removable sd card makes easy add lots music using philips pss120 similar sized unit outdated difficult use music interface 512 memory 5060 songs phillips unit better display black white versus simplyvibe blue black unfortunately simplyvibe display mostly worthless sun philips unit good 4 hours nonremovable battery whereas simplyvibe good 2 hours comparison 23 full volume simplyvibe removable cellphonelike batteries purchased 3 extra batteries5eaand charger 10 good 8 hours summary simplyvibe good sound lots volume replaceable lightweight batteries uses removable high capacity sd cards 100s songs would given 5 stars display useful outdooors