SIr freakinshoe69 . . . . .
If this is being it . . . .
https://www.amazon.com/DIY-Wireless...506277963&sr=8-10&keywords=fm+transmitter+kit
Hmmmmmmmmmmm looks like they are giving you two units . . .
Looks like its construction and following testing / evaluation will be an initial Baptismal under fire for you on RF oriented electronics..
The meager 3V power may give 10-15 ft range . . . with you having to try it to exactly see .
Also the simple circuit will be subject to hand capacitance / handling in a detuning of the operating frequency, so set up the "bug ?" into its fixed hiding place and tune in to its related frequency
WHEN distanced away from the unit..
The length of wire used as the transmit antenna . . .connected onto C7 will have an effect on range . . .initially, watch what info they suggest .
Since a short 6 inches is inadequate. . .but 25 feet is an INSANELY unrealistic assumption . . . that length would work even BETTER..
Also the signal propogation at the 108 high end of the FM band is better than the 88 low end, and at that 108MC end . . . a straight vertical wire antenna of ~36 inches length would be in order..
73's de Edd