The Shure BETA 181/O features a omnidirectional polar pattern capsule.

The Shure Beta 181 is an ultra-compact, small-diaphragm side-address condenser microphone, designed for discreet placement and control in live and studio environments. Featuring interchangeable cardioid, supercardioid, omnidirectional and bidirectional capsule options for superior versatility, the small diaphragm design provides superior audio with consistent, textbook polar responses in a form factor small enough to get close to the source in the tightest conditions..

Features

• Interchangeable capsules with multiple polar pattern options (cardioid, supercardioid, omnidirectional, bidirectional) deliver the ultimate in low-profile application flexibility
• Small diaphragm design provides superior audio with textbook polar responses in a form factor compact enough to get close to the source in the tightest conditions
• Precision-engineered, side-address design features innovative locking ring to provide secure connection between capsule and preamplifier with integrated XLR connections

The Shure 181 is ultra-compact, small-diaphragm side-addresscondenser microphone.  This 181 is so cool because it allows you to purchase additional interchangeable capsules.  Which makes the microphone super versatile both live and in the studio.  Pick between Cardioid, Omni, Super-Cardioid or Bi-directional capsules....or just pick up the 181 stereo kit and the possibilities become endless.