Rig tuning relies on accurate, repeatable results. Spinlock’s Rig-Sense has a composite lead spring calibrated to output loads to a direct linear scale. The readout, which is measured in kilograms, is simple to read and the one-handed operation allows one hand for the boat. It works with the Sense App, which is available for both iOS and Android, and allows users to record, store and manage critical settings in one place, as well as share them with crew or the whole fleet. www.spinlock.co.uk, $139