Sportjock from the United States:  Action Power Vest with Black exterior, white interior around bust area front and back, form fitting support sports bra which is pulled on over the head.  This Super Power Vest is the most comfortable bra you'll ever wear.  It is unbelievably cool on your skin because it is made with only the highest quality Dupont Spandex TM cotton or supplex: a quick drying material that releases moisture and keeps you dry.  This Sportjock bra gives you a natural, form-fitting support that makes you look and feel your active best.  Great for sports or warm weather outerwear.

The features:

Proven by Professionals to be the most supportive and comfortable bra you can wear for any activity.
Unique Power Band TM support system provides 7 layers of comfortable support.
Stylish racer or tank back.
Wear as outer or under garment
Double layer opaque material
No wires or plastic supports
Flexible yet supportive
Will not ride up
Inner layer wicks away perspiration
Original keyhole racer back allows ventilation
Logo guarantees you the original

This is a full coverage sports vest which will fit those with a A, B and C  cup size, high at the front to help minimise the upward motion of the breast when in movement.   Wide straps for comfort when supporting gifted breasts and the back is cut high so the straps will not slip off the shoulders.  Wide underband so it will stay in place.  The seams inside are covered and reversed.  The arm holes and the top of the front and back have the fabric turned under, secured with a double row of stitching.  The bottom has the edge turned up inside and secured with a double row of black stitching.

The lable says these are Washable on a cold gentle cycle, Colourfast (I did not find this true - the black did colour other items during the first wash so I recommend that this is washed separately the first two times, the black also made the white inside grey when washed.)    Line or drip dry.

We have received good feedback, and repeat sales, when we sold this brand in our shop

The body fabric is 86% Nylon/ 14% Spandex.
The lining fabric is 83% Nylon/ 17% Spandex.
 
Made in Costa Rica.   New and unused.  The RRP is £36.00