This is the weight balance parts for vertebra. since the spring was
made from stainless steel so that we have to enough weight for it.
we keep it more than 750g per part.
Customer like chromed one. we need high polish the surface and
chromed it. All chromed surface should be very fine. Since the
parts' thikcness are so big. so that we have to use big machine to
If it less weight then it means a lot of holes in side. we will
have trouble about the weight balance and cosmetic holes.
Normally this parts weight is around 870g. but acutally if we can
keep it over 680g then it is OK.