Gowoops Quad-Band GSM GPRS SIM900 Shield Development Board for Arduino

I have had good performance with this shield. Using hologram sim card everything has worked without issue. The only problem is that if you attempt to stack it on your arduino with stacking headers it doesn't fit because the sim card holder on the underside of the shield bumps against the USB port on the Arduino uno.

The product has a terrible design, It does not fit in arduino uno or mega, components are from bad quality. it didnt work and I dont have time to waste to return devices that doesnt work.

the product does not work

sim-card holder broken with first use. Connector speaker or microphone broken.

works.