Because the two batteries in the GGS. to the original Sennheiser BA151 (80mAh) are traveling only with 60mAh power, they make quite fast limp in practice, usually within 2 hours. They also go sit very tightly in the holders. Price - performance is ok but what you can for 4 / piece you expect ... I hope they keep at a low level at least one year from and do not go earlier in the knee.
