A 7T 8-channel transmit/receive volume head coil was designed, built, and tested. It is capable to produce transmit fields in the human brain of more than 50 µT when exploiting the RF peak power design limits. This high B1+ efficiency is necessary either for single voxel spectroscopy to reduce chemical shift artifacts or for pTx based feature selective excitation methods. The shielded decoupled loop array coil fits into B0 shim inserts and enables accommodation of optical stimulation equipment. From the simulation based design process appropriate input power limits were concluded, which allow safe operation of the coil in compliance with IEC 60601-2-33.Eight rectangular loop coil elements (L = 16 cm) were arranged (Fig.1) in a slightly elliptical fashion (A-P distance 250 mm, L-R distance 215 mm) within a cylindrical RF shield (OD = 34 cm, L = 396 mm). Loop elements were manufactured from a low loss PCB material (Mercurywave™ 9350) with 30 µm copper thickness. The coil former was 3D printed from polyamide powder using laser sintering whereas the slotted RF shield was supported by a GRP liner (Fig.2). Four capacitors were distributed along each loop element whereupon the capacitor at the feeding port was split to maintain symmetry. Two capacitors between adjacent elements were used to decouple the coil elements. The values for these capacitors were taken from previous simulations [1] and no further optimization was required. During commissioning only one variable capacitor per element was used for fine tuning of the element. Since for typical loading conditions the impedance at the feeding ports is around 50 ohms, no impedance matching network is required. True symmetric feeding was accomplished by a low-loss half-wave transmission line together with two quarter-wave lines all made from Sucoform 141 cable (Fig.3). An additional transformer line was used to ensure that the reference plane located at the SMA connectors exactly mirrors the conditions at the feeding ports. The coil was designed to withstand at least 1 kW of RF power per channel. B1+ measurements at a 7T Magnetom MR system (Siemens) were performed using an external Tx/Rx-switch box.After assembling of all coil elements and feeding networks fine tuning of each element was performed using the variable capacitors. This is usually done when the SMA connector of all other elements was left open resulting in an intrinsic decoupling. When terminating all ports with 50 ohms no retuning is necessary. A first validation experiment in a phantom [1] was performed using a B1+ mapping sequence and a prototype version of the coil (Fig.4). Considering that transmit field maps are susceptible to coil couplings and internal coil losses the measured and simulated transmit field maps are in amazingly quantitative agreement indicating that reasonable assumptions for internal coil losses were made in [1]. Taking into account this result a reasonable estimation of achievable peak B1+ values can be done (Fig.5). Due to considerable cable losses downstream the RF amplifier at 297 MHz only 5 kW from 8 kW of combined RF power is available at the coil plug. Nevertheless, the aspired peak B1+ values of 50 µT for the CP mode excitation are much higher than reported peak values for commercial 7T head coils [2]. For the CP mode, this maximum occurs in the center of the brain, but using the pTx capabilities of the scanner, it can be steered to other areas of interest with little loss in intensity. Key to this high B1+ efficiency was careful design and material selection, but also the choice of relatively short coil elements. The concomitant downside of limited whole brain coverage had deliberately been sacrificed for this dedicated MRS coil.A 8-channel pTx head coil optimized for MRS applications at 7T has been built. With realistic 5 kW of total RF power at the coil connectors, the coil is capable to generate close to 50 µT B1+ everywhere in the brain. This is needed to deliver high-bandwidth MRS pulses and thus minimize chemical-shift artifact in localized 7T spectroscopy. Using such strong B1+ fields generated by surface coils, neurochemical profiles were obtained from the occipital cortex [3, 4]. Providing this type of methodology in a volume coil would pave the way for a wide range of clinical and neuroscientific applications including the measurement of important neurotransmitters, such as glutamate and GABA.