There is some batches of sounddock portable speakers made in 2008/2009 and can charge iphone 2, 3, or 4 or ipod touch 2, 3, or 4 which most A2DP bluetooth music receiver are not compatible. This special model will be compatible with those sounddock portable. BT wireless range is between 50 to 60 ft for most tablets and ~ 25 to 45 ft for most cell phones. Support digital products using Bluetooth, such as iPad, iPhone, Bluetooth cell phones/tablets and PCs. This BT music receiver model with enhanced working distance (up to 60 ft) is twice of that of most similar devices sold on the market at ~18-22 ft. (For some cell phone with weaker bluetooth signal to save battery, the wireless range of this model is ~ 1.5-2 times of most other models if used on the same cell phone)Every unit is tested at 55 ft distance between Bose Sounddock Portable and Nexus 7 before shipping. )Other known compatible speaker models: · Altec Lansing iM600, iM7, iMT325, iMT620, iMT810, T612 · Beats by Dr. Dre Beat by Dr. Dre, Beatbox · Edifier M360, M35, M0, MKII, · Cyber Acoustics CA461 - Geneva Sound System Model L · Harmon Kardon Go + Play Stereo · iHome iA100, iA17, iA5, iA63, iD37, iD8, iD91, iH16U, iH4, iH5, iH6, iP1, iP4, iP9, iP11, iP37, iP90 · iLuv iMM747 · JBL On Stage 3, On Stage 4, On Beat, On Beat Air, On Time 200P, On Time Micro · Logitech S135i, S315i, S715i, Pure Fi Anywhere 2, Pure Fi Anywhere, S-0001, S135i, S315i, S715i · Memorex MA9010MS · Onkyo DS-A4 - Philips DC320/37, DCB291, DCB293, DCB352, DCD132, DCM2020, DCM230/37, DS1100, DS1200, DS3000, DS3510, DS7700 · Polk HD Radio I-Sonic · Pyle Home PiDock 1 · Skullcandy Skull Candy pipe, Vandal S7LACZ-04 · Sony AIR-SW10Ti, ICF-7iP, ICF-C05iP, ICF-C1iPMK2, ICF-CS10iP, RDP-M15iP, RDP-M5iP, RDP-V20iP · Yamaha PDX-11, TSX-70