Bluetooth location device - Prototype design

We are looking for someone to design a very small, flat bluetooth activated speaker device. We would like the initial prototype to be activated via a keyfob type design, although the device will eventually be one of many paired to a mobile device. The device must: * be able to be actived by the keyfob sending unit within at a minimum distance of 30 yards (Bluetooth 4.x) * be highly durable(enclosure) and impact and water resistant(entire unit) * The device must be battery powered * The device must emit a noise loud enough to be heard at a minimum distance of 50 yards with normal outdoor background noise * The device must weigh less than 6grams and have a max height of 6mm and max surface area of 12 square cm(3cm x 4cm would be fine, for instance). * The device must include an adhesive backing to attach it to flat plastic surface. The adhesive must also be durable and weather resistant. This quote is for the prototype design only, with deliverables including a sourcing list and approximate material and construction costs. This is to determine the feasibility of designing a 3-pack of these devices at approximately a $25-30USD price range. Please include a list of qualifications in any bid or response - further details will be provided to qualified candidates.