Used on high energy electronic or points ignition systems. Comes with a tapered edge for measuring gap. Gapping is done with center hole that will allow you to gap spark plug without pressure to center electrode. Measures and gaps from 0.020" to 0.100" (0.5mm to 2.53mm).
LISLE, TAKE-APART PISTON RING COMPRESSOR KIT
2-1/8" to 5" (54mm to 127mm). This Lisle clutch spring compressor, with take-apart feature, can be necessary for some motorcycles, outboard engines and cars (some VW). Can also be used on conventional engines with narrow ring spacing. For piston sizes of 2-1/8" to 5.00" (54mm to 127mm).