BAR-L TEMPERATURE STRIPSIf you shoot enough to cause your barrel to heat up, you should have an idea just how hot your barrel is. Nothing can destroy a barrel and accuracy faster than an overheated barrel. These strips can be permanently fixed to the barrel with the heavy duty clear plastic tape strip provided with the BAR-L TEMP STRIP. Three ranges to choose. Moderate Zero reads from 32F to 86F. Benchrest reads from 86F to 140F. General Purpose reads 86F to 194F. The strips are easily read. If the box is green, that is the temperature of the barrel. As the barrel gets hotter, the next block goes from black to green. The previous block goes from green to black. NOTE: these will ship in an envelope for about $ 3 - ignore the shopping cart calculated shipping.