Tired of out of sync and need to re-sync if walking out of the bluetooth signal working range ( ~ 20 ft), This Apr/2016 newly released bluetooth adapter is the solution. It can memorized two devices, not just one as other brand.
This new model has enhanced wireless working distance (up to 75 ft), twice or even triple of that of most similar devices sold on the market at ~18-25 ft. (For some cell phone with weaker signal to save battery, wireless range is much improved with this new model. The wireless range of this model is ~ 2 to 3 times of most other models)

Known compatible speaker models:
• All Bose speakers with 30 pin dock, sounddock original, I, II, 10, portable.
• All speakers with 30 pin dock and auxillary 3.5mm input. If the 30 pin dock is not compatible, plug this bluetooth adapter on the 30 pin dock to provide electricity to this bluetooth adapter. Use the included 3.5 mm audio cable to connect this bluetooth adapter to aux audio input of speaker, which usually locate at the back of speakers.
• Built in 12 volt converter so this device works for both the old 12 volt 30 pin dock (made before 2009) or the newer 5 volt 30 pin dock (made after 2009)

Convert Aux Headphone to Bluetooth Headphone
Plug your headphone to the Aux Input of this bluetooth adapter. Pair with your iphone 7 or any cellphone with Bluetooth function. Your headphone becomes a Bluetooth headphone immediately.

What is included:
1. one 2in1 bluetooth music receiver
2. one 3.5 mm audio cable
3. one 3.5mm to RL stereo audio cable

Instruction Video: https://www.youtube.com/watch?v=MMCGic1kBQM

• * EXTRA LONG BLUETOOTH WIRELESS RANGE. CAN PAIR WITH 2 DEVICE* Revised Apr 2016 new Bluetooth 4.0 model with even better bluetooth wirless range, voice instruction for pairing and can memorize two bluetooth devices (not one). The wireless range of this model can be up to 75 fts. This unit has the longest Bluetooth wireless range when compared with other similar models.
• * WORK FOR ALL APPLE AND ANDROID PRODUCTS W BLUETOOTH FUNCTION" Compatible with iPhone 6, 6s, 5, 5s, iPad, all other Apple products, Samsung Galaxy, HTC, Moto and all devices with Bluetooth function. Stream music from any Bluetooth enabled device. This model comes with an on/off and incoming phone answer button. So no more plug and unplug to activate this bluetooth receiver. * BETTER COMPATIBLITY. * Built-in 3.5mm Auxiliary Jack for connecting this 2in1 with Sony, Beats, JBL, Yamaha, iHome, Altec Lansing, other Digital Docking Stations, Stereo Receivers and Car Stereos with Auxillary input or RL audio input. 3.5mm aux cable and 3.5mm to RL audio cables are included in the package.
• * EASE OF USE. PLUG, PAIR AND PLAY * Don't throw out your expensive dock. Stream music wirelessly to your iPhone / iPod docking station by plugging our Bluetooth music receiver into the 30 pin connector. Compatible with Bose SoundDock original, Digital I, II, Portable, SoundDock 10 and Wave with optional 30 pin docks.
• Because it is difficult to make the bluetooth adapter to be compatible with all 30 pin speaker, we have added aux output choice for this model. If this device is not compatible with the speaker through the 30 pin dock, just use the included aux cable to connect to the aux input of the speaker to make it work. This instruction is in the product manual and also in the jpg product picture in the amazon product web page. As for Bose digital III with 8 pin dock, this product cannot work due to different connection pin.
• CONVERT AUX HEADPHONE TO BLUETOOTH HEADPHONE TO WORK WITH IPHONE 7 OR ANY CELLPHONE * Plug your headphone to the Aux Input of this bluetooth adapter. Pair with your iphone 7 or any cellphone with Bluetooth function. Your headphone becomes a Bluetooth headphone immediately. No need to buy another expensive Bluetooth headphone.

* EXTRA LONG BLUETOOTH WIRELESS RANGE. CAN PAIR WITH 2 DEVICE* Revised Apr 2016 new Bluetooth 4.0 model with even better bluetooth wirless range, voice instruction for pairing and can memorize two bluetooth devices (not one). The wireless range of this model can be up to 75 fts. This unit has the longest Bluetooth wireless range when compared with other similar models.BMRMusicTechnology