Blackstar HTV-112 Guitar Cab The Blackstar HTV 112 MKII open-back 1 x 12" extension cabinet gives you the British-voiced tone you've been looking for. No matter what electric guitar amplifier you plug in, you'll love the sound of this guitar cab's balanced sound across the spectrum, making it a great choice for any style you play. That's all thanks to the Blackstar HTV 112 MKII's real Celestion speaker. Built tough and ready for the demands of the road, the Blackstar HTV 112 MKII 1 x 12" extension cabinet is a powerful addition to your rig.