Innovative Products Of America 7880 6" Long 14mm Thread Top Dead Center Indicator Accurately displays piston movement 1/8 inch graduation marks Installs as easy as a spark plug Made of 1144 steel with a stainless steel spring Lifetime warranty; made in the U.S.A. The dimension of this product without package is, L:6.25" W: 0.57" H: 0.57" Accurately displays piston movement 1/8 inch graduation marks Installs as easy as a spark plug Made of 1144 steel with a stainless steel spring Lifetime warranty; made in the U.S.A.