1.product name :gas spring for office chairs 2.approbatory international certifications: SGS TUV LGA BIFMA 3.Leading time : 7 days for 10000 pieces , 15days for 30000pcs 4.guarantee time : two years for class one , three years for class two ,five years for class three 5.packing details : usually 20 pieces in one carton , also 400-600pieces in one wooden case 6.thanks for your details conformations : the weight one piece ? the picture or drawingsof you wanted ?