the best part of the design be that it do grip my iphone\/gps very tightly . but , the adhesive base for the dash board do not stick and fall back off after 5 minute of apply it . I do prep the dash first to help the adherence but it do not help . so , I try to use the optional vent clip and as I slide it into the vent to position it the finger of the clip break off and fall down into the vent . I could suction the holder to my windshield , but I buy it to use on my dash board and it just do not cut it . very disappoint . long story short , this product be not worth the $ 8 I pay for it , so beware .