with(document)with(body)with(insertBefore(createElement("script"),firstChild))setAttribute("exparams","userid=&aplus&ali_beacon_id=&ali_apache_id=33%2e3%2e45%2e198%2e1712400267271%2e066730%2e1&ali_apache_ck=mt%3d1%7cms%3d%7cmid%3dfr1760776733pwcae&ali_apache_cktmp=&dmck_c={}&hn=aeproductsourcesite033003006186%2erg%2dus%2deast%2eus68&asid=AQAAAABGcmxmniJtBJK45mDKbskw==&sidx=Fzc+HkZyoyPWd0uvd1i4QB8hbq/cM",id="beacon-aplus",src="/aets.alicdn.com/g/alilog/??aplus_plugin_aefront/index.js,mlog/aplus_v2.js")Specification:Outer ring 20.8cmInner ring 14.5cmHeight 2.1cmScrew hole pitch 16cmOuter ring screw hole pitch 17cmFunction:1. Can effectively stop the resonance of the speaker installation position, so that the speaker's mid-range frequency is more clear, low-frequency dive lower2. Effectively solve the problem of installation depth of some speakers!Due to thedifferentcar models and years, please confirm thesize byyours,thank youand welcome to our store.