The necklace is a pendant shaped transmitter that attaches to the base of the neck riding over the region of the bird's crop. The necklace portion consists of PVC tubing covering a coated, braided stainless steel flexible cable. The cable fits through two holes, one on each side of the transmitter. A metal sleeve is crimped to the cable on each side to hold the transmitter in place. The antenna either extends upward from the body of the transmitter over the bird's head or runs within the PVC to the top of the necklace and then exits the PVC extending upward. To make the antenna less obvious, some researchers bend it over but not touching the bird's back .

A necklace transmitter is the most common attachment method for pheasant, prairie and woodland grouse, quail, partridge, and increasingly, turkey. This attachment is rapidly replacing the Brander and backpack attachments of the past. The necklace provides a better fit if adjusted for size at the base of the neck instead of being slipped over the bird's head. The necklace transmitter rests over the bird's crop which is an area on the body where the bird gains and loses weight during daily feeding and digesting processes. A transmitter can be removed from a dying bird and attached to a new study animal in minutes by retying the necklace in the field. Ease of attachment reduces time and stress caused by handling. Other advantages are increased field range because the antenna is positioned vertically and no encumbrance of the body or wings which can cause behavioral problems.

The new M1500 and M1505 Zip-Ty transmitter series are labeled "Mammal" on the specification sheet, however the models are used interchangeably between species. These newly designed models feature a Zip-Ty necklace in place of a flexible cable, making for very easy field use.

 

Series	Weight (grams)	Life (days)	Description
M1500	1.4-4.8	15-468	Smallest sizes, reduced power output for longer life, minimum potting for lowest weight., silver oxide battery. NEW Zip-Ty / PVC collar. Limited frequency availability.
M1505	6-34	65-2036	Small size, standard power output for normal life, normal potting for durability, silver oxide battery, cylindrical shape. NEW Zip-Ty / PVC collar.
A3900	4-16	119-926	Coin shape, lithium battery, adjustable collar material provided.
A4000	7-30	24-950	Cylindrical shape, lithium battery, adjustable collar material.
A4100	12-25	60-553	Flat shape, very thin profile, lithium battery, adjustable collar material.